Syndicate
50 Achievements
1,000
40-50h
With Friends Like These
Kill an enemy from the explosion of a reactive armor unit
15
How to unlock the With Friends Like These achievement in Syndicate - Definitive Guide
but this strategy worked great, exactly where I picked up the achievement.
A good place to do this is Chapter 8. Here you will encounter your first enemy equipped with reactive armor unit, which is white in color and looks bulky in size. You can't miss this battle. The enemy you are looking for is heavily armored, bigger than all other enemies and uses a minigun. When his health bar is depleted he will explode. Once that happens you must make sure other enemies are nearby (so don't kill them yet!). At least one other enemy has to die from the explosion. If it didn't work you can reload the last checkpoint and try again.
The first time you can get this achievement is on Chapter 8 and best played on easy (just so you don't have to worry about the lackeys). You'll know you're at this point when you encounter a cutscene with a big, white armored guy holding a minigun. Breach the big guy's armor and shoot his health down, then do the same thing again. When you have breached him twice and shot down his health, lure him over to a lackey and breach him one final time. His explosion should take out his friend, and you will get the achievement immediately. If for some reason you fail, you can also reload your checkpoint and start right at the beginning of the fight.