ADVENT Purifier | Enemies XCOM 2: War of the Chosen Game Guide

You will encounter ADVENT Purifier early on in the game. Those guys were created to fight the Lost - every Purifier sports a flamethrower and incendiary grenades, which enables them to damage and burn their enemies. They have pretty good area of attack, which enables them to attack a couple units at a time, but poor range, which forces them to close in - making them an easy target.

ADVENT Purifier.

Here are a few tips that ought to help you fight this enemy:

1. The opponent has a chance to blow himself up upon death. It doesn't happen every time, but it's important to keep this in mind and don't send units that attack him at a short distance. If you have troops nearby, try to keep them away before you attack.
2. Since they can blow up, they will be even more problematic during missions that involve the Lost - any explosion is sure to lure in a lot of them. Bear this in mind.
3. This enemy has very short range; hence the most efficient way of tackling them is to order somebody with good range - a sniper or a Reaper - to take care of the problem, while keeping units with poorer range at a safe distance.
4. Anti-armor projectiles will also come in handy - the enemy doesn't have much HPs, but may have as much as 3 armor points, which should enable them surviving at least one regular attack.
5. Most importantly: spread your troops if you're fighting the Purifier - otherwise he'll be able to easily ignite a couple of your soldiers.