XCOM 2: A Guide to Defeating Every Type of Alien in the Game Part 1

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As a long-time veteran of the series, I was delighted to see that Firaxis opted to make XCOM 2 even more challenging than its predecessor. In spite of the fact that Enemy Unknown was a pretty difficult game in its own right. Not only are we constantly in a battle against time here, but some of the new aliens are also considerably tougher to take down and even the old ones have a few new tricks up their proverbial sleeves.

The game is designed in such a way that you get to learn about your enemies only after you take one of them down and bring it back to the lab for analysis. Although this makes perfect sense in the context of XCOM 2, it doesn’t really help you that much if you want to know all there is to know about the aliens beforehand. Thus, I took what I learned from playing over 200 hours of XCOM 2 and created a comprehensive guide aimed at helping rookies who might be a bit overwhelmed by the game’s difficulty and veterans doing an Ironman playthrough where underestimating the enemy can easily lead to losing soldiers in a heartbeat or even losing the whole game.

We will not be discussing any ADVENT troops here because they are only partially alien and most of them are fairly easy to dispatch by regular means so let’s just save some time and start talking about the actual aliens, shall we?


The Sectoid has been a staple of the series since the very beginning, though the variant you’ll come across in XCOM 2 is quite possibly the most dangerous one so far. This time around, the Sectoids are taller, more humanoid in appearance, and have quite a bit more health than in the past. As always, you won’t have to worry too much about their plasma weapons so instead focus more on avoiding their psionic abilities, particularly Mind Control, which you’ll now have to deal with very early in the game.

The Sectoids are also capable of disorienting your soldiers or cause them to panic and miss their turn. A new ability called Mindspin allows them to initiate a psionic attack that can have any of the aforementioned effects (including Mind Control), though the chance of each will be smaller because it seems to choose between them at random. Last but certainly not least, the Sectoids can now reanimate corpses and create Psi Zombies, which can be very dangerous in their own right if they get within range.

Needless to say, you’ve got your work cut out for you when fighting these guys in the early stages of the game because all your soldiers will likely have low Will and are therefore highly susceptible to psionic abilities. A pretty obvious option would be to equip your guys with Mindshields or Focus PCS in order to gain more Will. However, it would be pretty expensive to get that stuff for all your soldiers so a better alternative would be to forget about defense and just go on the attack.

Your Rangers will be invaluable in this situation since their melee weapons do double damage against Sectoids while a well-placed Flashbang or Incendiary Grenade can prevent the aliens from using their psionic abilities altogether. In addition, Flashbangs can also cancel Mind Control and kill Psi Zombies if the grenade hits the Sectoid who reanimated them. As a general rule, you should always try to kill or disrupt the caster instead of wasting time with the zombie because killing the caster immediately gets rid of the zombie as well.


Contrary to its name, this alien species looks more like a cobra than a viper, though the name is the last thing you’ll have to worry about when facing it. According to the developers, Vipers are Thin Men showing off their real form now that they don’t have to act as an infiltration unit anymore. As it turns out, their true form is actually quite resilient and capable of dishing out even more damage than the Thin Man with its beam weapon.

In addition, the Viper also has a pretty nasty Poison Spit attack that will inflict damage over a number of turns if not treated. But perhaps most annoying is its Tongue Pull attack, which snatches a soldier from a considerable distance and is then followed up by the Viper’s Bind and Crush ability. Bind and Crush does both initial damage and an additional 2-3 damage per turn until something interrupts it or the victim is dead.

Similar to most aliens, the Viper will first attempt to use its abilities before resorting to its beam weapon so make sure to plan accordingly. Poison Spit is relatively easy to counteract by simply using a medkit on the afflicted soldier, but make sure to act as fast as possible because the poison inflicts 1-3 damage for up to three turns if left unchecked and that’s definitely something you’ll want to avoid.

As for the Tongue Pull, it’s pretty difficult to avoid entirely because of its range and the fact that the Viper doesn’t always choose the closest soldier as its target. But if you can, staying as far as possible does tend to help. Since this is XCOM 2, though, something will inevitably go wrong from time to time so it’s good to know that damaging the Viper for any amount will cause it to release the bound soldier.

Combat Protocol, Flashbangs or any other disrupting ability can also do the trick. If that’s not an option, at least try to heal your bound soldier or make them more resilient by using an ability like Aid Protocol. Alternatively, you can use a Mimic Beacon and trick the Viper to go for the hologram instead of your own soldiers.


The Muton is perhaps one of the most straightforward and predictable of the aliens but that doesn’t mean you should underestimate it. Mutons usually travel in small groups and carry both plasma rifles and plasma grenades with them. Blood Call and Intimidate from the original game have been replaced in XCOM 2 with Counterattack and Execute, two abilities that are geared primarily towards dealing with your melee soldiers. Execute allows the alien to insta-kill an adjacent stunned unit while Counterattack gives the Muton a high chance to block a melee attack and immediately respond with one of its own.

Needless to say, under no circumstance should you rush in with your Ranger for a melee attack because it will end very badly more often than not. Don’t go in with your sword even if the hit chance is 100% because that doesn’t take into account Counterattack. To make matters worse, the Muton also has Suppression, so getting close to it in the first place can be difficult sometimes. Execute won’t usually be a problem but be sure to act immediately if a soldier gets stunned near a Muton regardless because otherwise it can very easily lead to an insta-kill.

Aside from keeping a safe distance, it’s also highly advisable to not keep your soldiers all clumped up because the Muton’s plasma grenade deals 4-5 AoE damage and shreds 1 armor. The Mutons have armor themselves so if you have a Grenadier with Shredder don’t hesitate to use it. Unlike some of the other aliens in XCOM 2, the Mutons don’t have any easily exploitable weaknesses and disrupting their abilities is only partially effective because they can still shoot for 4-6 damage and 1 shred with their main weapon, though you can potentially hold your own in a firefight by using Smoke Grenades and Aid Protocol on your most vulnerable units.

In short, you’ll generally have to fight Mutons the old fashioned way. Luckily, by the time you first encounter them you should already have at least a few decently equipped soldiers so be sure to use every trick in the bag against them. In the later stages of the game I would highly recommend using Mind Control because Mutons make great allies.


The Berserker is back and she’s more fearsome than ever before thanks in no small part to the extra muscle mass she managed to gain since Enemy Unknown. When it comes to stats and abilities, however, we’re looking at only relatively small changes. Berserkers have one of the strongest melee attacks in XCOM 2 and are able to sustain a good amount of punishment before going down.

Their abilities are all centered around closing in and delivering devastating blows that not only deal a huge amount of damage, but can potentially also disorient or stun your soldiers. In addition, they also have a chance of being enraged when wounded, which gives them a temporary but pretty beefy boost to their mobility and damage. Aside from that, there’s not much to worry about when it comes to special abilities because they don’t really have any.

Since Berserkers can only attack in melee, it should be pretty obvious that you should only engage them from afar and instead, make good use of high ground whenever possible. Unlike Mutons, the Berserkers won’t counterattack if you do decide to get close with a Ranger, but make sure you know what you’re doing if you go down that path because the next turn could be the last for that particular Ranger.

The best course of action is to focus everything you have on a Berserker the moment you first see it by using high-damage abilities like Deadeye or Chain Shot and items like Talon Rounds, Incendiary Bombs, or Proximity Mines. The Proximity Mine won’t actually detonate during the same turn you plant it, but it will go off immediately when the Berserker moves next turn and will deal 8 damage. On paper, it sounds like Berserkers are a pain to deal with, however, in reality the lack of armor makes them fairly easy to take down before they can do any serious damage provided the whole squad focuses on them.


The Faceless is a new
type of enemy introduced in XCOM 2 that replaces the Thin Man in many ways and
acts as an infiltration unit. Though not very dangerous once revealed, Faceless
look exactly like regular people until you get close to them and make civilian
rescue missions even harder than they already were. Upon assuming their real
form, these tall gelatinous aliens are able to deliver AoE attacks with their
huge claws and leap straight on top of buildings or other elevated surfaces.
Not only that, but they can also regenerate some of their lost health at the
end of their turn if left unchecked.

The attacks themselves are not all that dangerous because they usually only inflict 3 damage, but it’s still better to avoid them if you can as they can hit multiple soldiers at once. The Faceless only have a moderate amount of health so Regeneration won’t become a major issue unless you aren’t able to kill them quickly for some reason. Merely killing them isn’t too much of a problem since they don’t have any armor and their defense stat is 0, however, the main advantage of the Faceless is that you can’t actually see them until it’s too late.

During rescue missions, inching your way across the map and constantly having a few soldiers on overwatch in order to be prepared for potential Faceless isn’t as good an option as it sounds because a lot of civilians will die if you take too long and you may even lose the mission. Instead, it’s better to bring along a Battle Scanner and a Specialist with Scanning Protocol and just try to reveal the Faceless before they have a chance to take you by surprise.


Yet another staple of XCOM is the Chryssalid, a unit that you are surely very familiar with if you’ve played some of the previous titles. From a physical standpoint, these aliens have suffered very few modifications since Enemy Unknown. In fact, they look pretty much the same save for the color and a few extra spiky features. Their abilities, however, are a different story altogether. But don’t worry because their most iconic ability which can transform a soldier into a Chryssalid is still here and it’s stronger than ever because now it spawns three aliens instead of just one.

On the bright side, the drawback for the insect-like alien in XCOM 2 is that its victim has to die from its poison and not its slash attack. This means that you will have a few turns to react before things turn sour, but make sure you still act quickly because three Chryssalids spawning from one of your soldiers is the last thing you want. In addition to these changes, the aliens can now burrow as well, which makes them invisible until detected or until they decide to show themselves.

Fighting a Chryssalid is similar to fighting a Faceless in some ways as you’ll need to make good use of abilities like Battle Scanner and Scanning Protocol in an attempt to reveal them. That said, Chryssalids will not always be burrowed and usually go straight for the attack in groups of two or three at the same time. Even if you won’t need to use any scanning abilities, a Specialist will still be crucial when going against them because they can heal your poisoned soldiers.

The Chryssalid seems to be able to use a special kind of poison that doesn’t expire after a certain amount of turns, so again, bringing a healer is very important. Chryssalids are immune to poison themselves, which makes sense. Given that you’ll often find these aliens in packs, most types of grenades and AoE abilities are very useful for getting rid of them in one go. In addition, Rangers with the Bladestorm ability are great for dealing with Chryssalids and can sometimes one-shot, or at least, stun them (depending on the weapon) before the aliens get a chance to attack.


At first glance, the Archon seems like a brand new unit that looks unlike anything we’ve seen before in an XCOM game. While that may be true to some extent, upon closer inspection it would seem that the Archon is just a highly improved version of the Floater. And I do mean highly improved. Not only is this alien capable of flying above the battleground, but it also has health for days, both melee and range attacks, as well as two abilities called Blazing Pinions and Battle Frenzy.

Battle Frenzy gives the Archon a chance to gain an extra action point when enraged while Blazing Pinions is a powerful AoE attack cast from above. On top of it all, this alien also comes with high mobility and a decent dodge stat. The Archon is one of the most well-rounded enemies in XCOM 2 so killing it will not be a walk in a park no matter how you look at it.

First and foremost, the Archon’s abilities are not as dangerous as they sound, especially Blazing Pinions, which can easily be avoided due to its one turn delay. Just make sure your soldiers are outside the area of effect and everything will be just fine. On the offensive side, you need to make sure that you attack the Archon head-on with high damage attacks and ideally kill it before it hits you because its 7-8 damage ranged and 6-9 melee attacks are nothing to sneeze at.

While the Archon doesn’t appear to be too tanky when you first meet it, its health scales considerably towards the end game. On the other hand, this is precisely why the Archon is one of the best targets to use the Psi Operative’s Dominate on. You will need a powerful Psi Operative, though, because the Archon has very high Will. But if you do manage to control it, you’ll have one of the best possible allies at your side for a few turns. If that’s not an option, you can always use a Mimic Beacon to draw away fire, though simply setting up an ambush with lots of soldiers on Overwatch might be a better alternative depending on the situation.

As a side note, the Archon has high accuracy while airborne, however, the lack of cover up there makes it very vulnerable. Therefore, the best moment for a full on attack is often during the same turn it casts Blazing Pinions. But be advised that killing an Archon doesn’t stop the ability so you’ll still need to get out of the way regardless.


The Andromedon is one of the toughest enemies you’ll have to face in XCOM 2 and not only because of its high damage and health, but also because you’ll have to kill it twice. It’s unclear if these aliens are actually from the Andromeda galaxy but it’s pretty obvious that they come from a very different world given that Earth’s atmosphere is toxic to them. As such, Andromedons wear protective environmental suits in battle that continue to fight by themselves even after the pilot is killed.

The suit itself is a little less dangerous than the piloted version. However, killing the pilot will prove to be quite difficult as it is equally dangerous in both melee and ranged combat while also being capable of destroying cover and throwing devastating Acid Bombs.

By far the easiest way to deal with an Andromedon is to use Mind Control and have it fight other strong enemies until they both go down. Keep in mind, though, that only the first phase counts as an organic unit and Mind Control will be lost once the second phase starts. That said, the suit itself is considered mechanic so you’ll have plenty of options to deal with it, such as Haywire Protocol, Combat Protocol, Capacitor Discharge, EMP Grenades, Bluescreen Rounds and more.

The suit is relatively slow and only uses melee attacks, which makes it much easier to take down if you’re using abilities and items that deal extra damage to robotic units, such as the ones mentioned above. As for the first phase, if Mind Control isn’t an option the first thing you’ll need to consider is quickly getting rid of the 2 armor and spreading your soldiers around the map to avoid the acid bombs. Getting rid of the armor is easy with the Grenadier’s Shredder ability or with Acid Bombs.

Interestingly enough, the Andromedon is actually immune to acid damage but Acid Bombs/Grenades can still shred its armor so don’t hesitate to use them. Mimic Beacons are again a great item to use because they can buy you some much needed time while Flashbangs are also very useful for preventing the Andromedon from using its acid bomb. However, make sure to have a medkit at hand just in case you do happen to take acid damage.


One of the most original and deadly enemies in XCOM 2, the Gatekeeper appears as a mass of tentacles encased inside a metallic sphere. While it may not seem like it at first, this is one of the most powerful psionic units you’ll have to face on the battlefield and also one of the most heavily armored ones. One of the nastiest abilities you’ll need to look out for is Gateway, an AoE psionic attack that does lots of damage and also transforms any corpses into a Psi Zombie, including your own soldiers.

What’s more, the Gatekeeper has a very powerful beam attack that deals 9-12 damage and an armor rating that can reach no less than 7 in the latter stages of the game. However, the high armor rating only appears when the Gatekeeper is hardened, a protective state that prevents it from using its dangerous psionic abilities, but makes it a lot more difficult to take down. Finally, the Gatekeeper also destroys cover as it passes through and is capable of restoring a portion of its health by using a melee attack called Consume.

Despite all its abilities and raw power in pretty much every department, the Gatekeeper also has quite a few weaknesses that can be exploited by the player in any number of ways. Most importantly, the Gatekeeper is considered both an organic and a mechanic unit and as such is vulnerable to a wide range of abilities, including Mind Control and Hacking, which should definitely be used first whenever possible. If those fail, the player should concentrate on shredding the armor with appropriate abilities and utility items, with Acid Bomb being by far the most efficient.

Thanks to its semi-mechanical nature, the Gatekeeper is a prime target for abilities and items and do extra damage to robotic units, such as Bluescreen Rounds, EMP Bombs/Grenades, Combat Protocol or Capacitor Discharge. Furthermore, Flashbang and Incendiary Grenades should be used in order to prevent the Gatekeeper from using its powerful abilities. Depending on its Psi stat, a Psi Operative can also use abilities like Insanity or Void Rift for a similar effect.


Initially, I didn’t want to include the Codex in this guide because it is an important part of the story and I didn’t want to spoil anything (same goes for Avatars), however, I think just a couple of tips might be useful since this is one of the most annoying enemies you’ll come across in XCOM 2. The Codex can teleport anywhere on the map and Clone itself when damaged, the second unit appearing at a seemingly random spot on the battlefield. However, upon cloning itself the alien also splits its health in half, which makes an individual easier to kill, though you’ll still need to deal with two of them.

Apart from that, the Codex also has a pretty powerful plasma weapon that becomes even more dangerous when the unit teleports itself to a position from where it can ignore your cover. Last but not definitely not least, the Codex loves to cast Psionic Rift, an AoE ability that disables the weapons of soldiers caught within and deals psionic damage when it expires.

Ideally, you’ll want to keep things from getting out of hand by using a Flashbang in order to prevent the Codex from using its abilities in the first place. Incendiary grenades will not accomplish the desired result because the Codex is immune to burning. Do that and the rest of the fight will be easy because this is one of the weakest aliens in terms of health and it also lacks any armor. Alternatively, Mind Control is a very viable option that will also enable you to get an excellent scouting unit on your side if you can pull it off. If you simply want to kill it quickly, “one shot, one kill” abilities like Deadeye or the Ranger’s melee attack are usually the best way to go.

Luckily, the Codex is also considered a robotic unit and you can use this to your advantage by employing appropriate abilities and items should you fail to kill it in one go. Faceoff and Reaper are two other great abilities here because they can be used to take down multiple clones very quickly due to their low health.

As for Psionic Rift, if you can’t prevent the Codex from casting it you should get out of the affected area as soon as possible to avoid getting your soldiers damaged by the upcoming blast. Although the ability seems to disable weapons, it actually only drains their ammo. Just move away from the area and reload to get your soldiers back into the fight.

Want to learn more about XCOM 2? Check out our review right here.

This article was originally published on geeksnack.com on March 1st, 2016 before the site was taken down the following year.

Jason Moth

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