Don't You Die On Me!
How To Unlock: Revive another player in Co-op.
- When facing a psychopath, allow him to down your partner. Damage the psychopath enough to where he/she retreats so that you have a chance to revive your partner for an easy 20 Gamerscore or a Bronze trophy.
- When in a game where both of you do not have this, just ask him to allow you to down him and revive him, and then allow him to do the same. Both of you get the achievement/trophy.