The first STALKER game, Shadow of Chernobyl, had a quest where you were supposed to save some scientist guy from a bunch of mercs. You could, in fact, choose to let them kill him and proceed anyway. If you did save him, you'd have to escort him to the edge of the Ecologists' (scientist guy's faction) territory. He even tells you he's a shit shot and apologizes for being dead weight.
Which is blatant lies. His weapon is a shitty broken submachine gun, but if you give him at least a Kalash, he goes all White Death and pulls off headshot after headshot on the incoming mercs. Has a lot of health too, so he's not very likely to die either. You can basically follow him around and watch him murder fools left and right.
Good times.