X-Men: Destiny
50 Achievements
15-20h
Purify the Purifiers
Defeat 2000 Purifiers.
5.9%
How to unlock the Purify the Purifiers achievement in X-Men: Destiny - Definitive Guide
Now this achievement is easy and simple enough, but fairly time consuming. Even after two whole playthroughs in the game I found myself at about 1700 Purifier kills.
The best way I found to farm these kills is to set your game on the easiest difficulty and just keep doing challenge number 9, where you are factioned with the Brotherhood and helping Quicksilver seek revenge after being locked up in the cell. This challenge gives you lots of Purifier kills, and even a Prime Enforcer kill to work towards the Reinforced achievement.
Hope this helps!
EDIT: This achievement actually doesn't stack between different characters, but does between multiple playthroughs of the same character.
CREDIT: Kaiser679
Purifiers are an anti-mutant extremist faction. They are the most common enemies that you'll face throughout the majority of the game. By the end of your first playthrough you'll have over 1100 Purifiers defeated, even more Purifiers will be defeated as you're farming the other uncommon types of enemies from the challenge missions. It's also important to note that once you've beaten the game and the credits roll, you'll be able to defeat over 200 Purifiers while the credits are still rolling. These defeats will also count towards your 2000 Purifiers defeated. To keep track of all your statistics simply press the button and then
In order to farm defeats more quickly, simply replay Challenge Mission 9 to defeat 99 Purifiers along with 1 Prime Enforcer.
In 2 minutes you will receive 99 Cleaners and 1 Prime Reinforcer.