Deathstroke being in Injustice would probably be one of the weakest reasons for it to be not be T-rating. Man, the missing flesh pieces (especially on Doomsie, that poor guy) scared my mom out of her wits.
And it still has a T rating.
"Ponies." - Ares Best Posters I've Seen (to date; ongoing): CAW Evolution
Oh come on. No one comes back from the joy buzzer or gunshot!
I agree that they shouldn't be alive after that; anyone shot with Joker's gun should either be dead, or Oracle. It's actually possible to kill Arkham guards as Batman by dunking them in electrically treated water (though you will fail the mission), but player-controlled Joker can't kill anyone under any circumstances. Maybe he thinks the irony is funny.