X-Men: Destiny
50 Achievements
15-20h
Reinforced
Defeat 20 Prime Enforcers.
4.6%
How to unlock the Reinforced achievement in X-Men: Destiny - Definitive Guide
To replay a challenge mission just go to load a game on your character and select the challenge list, it is the one with the X-men/Brotherhood symbol on it the ninth one if you look at them going left to right. Should be a good way to grind out the achievement.
Just pay a bit attention that you kill him as soon as possible so that quicksilver wont steel him. While you work on the 20 Enforcer you should also get the achievement for 2000 Purifiers.
Prime Enforcers are Purifiers that were anti-mutant suits that are identical to the first boss fight's suit, Cameron Hodge. In fact, Prime Enforcers have the exact same attacks as Cameron Hodge. You'll first encounter Prime Enforcers in Mission 4: Mutant Rescue if you accepted either the Quicksilver or Colossus challenge mission. This challenge is Challenge Mission 9 were you'll have to defeat 99 Purifiers along with only 1 Prime Enforcer. You encounter more as you playthrough the story mode. In order to defeat them you must first disable their force field then simply attack them to inflict damage to its health meter. To keep track of all your statistics defeats simply press the button and then .
In order to farm defeats more quickly, simply replay Mission 7: Mutant War. This mission has 6 Prime Enforcers for you to defeat.