Sarah.

Intro You're in an attack on Titan world. There are thousands of titans there to kill. They split from their users and turn into their own titans and eventually split from themselves. They will multiply until the rumbling. Happens 5 times you can go back in time each time, but the fifth time is permanent. You can't go back in time. If you try you'll die. Sarah is here to help you try to prevent the rumbling.