Goblins

Though calling them a faction is a bit generous, it cannot be denied the effect that goblins have on the populace. The life of a goblin is often fast and bloody, these mindless creature delight in the pain of others and will just as readily kill each other if there are no prey around. Goblins aren't so much lead was fired off in a general direction, and fired off can as often be literal as figurative.

There are often groups of goblins that are lead by the biggest goblin, or something else strong and stupid (goblins do not make the best henchmen so smarter leaders will generally shy away from them)