Kyubey: Make a contract with me and become a magical girl. All it takes is a wish.
Eren: A wish?
Kyubey: Yes, any wish. You have enough emotional energy to do so. So, do we have a deal?
Eren: *nods* I wish, to able to KILL ALL THE TITANS!!!
Kyubey: The contract has been sealed. Eren Jaeger, you are now a magical girl. Until your soul falls into despair and you transform into a witch.
Eren: Wait, wha- *transforms into titan form, but is wearing a fluffy, pink dress and pigtails with ribbons* ROOOAAARRRR!!!!!