We now know that Marley is responsible for the sending of undesirable Eldian citizens to Paradis as mindless Titans, doomed to wander the island in search of food.For most of the series we were led to believe that titans were monsters that drew pleasure from devouring humans then we learn't of shifters and now we learn who the titans are.
In the beginning Eren swore he'd wipe of all titans in his revenge for the destruction of Shinganshina but we now know these mindless beasts are unjustly oppressed and punished Eldians,the false antagonists.
But even then it's kill or be killed,once these creatures encounter any human they attack and aim to eat them.
Even still knowing this is still okay to kill these pitiful creatures anymore?