Maybe Ymir was a normal Titan, but was somehow rescued by Christa?
she is so scared of turning back into a mindless titan that she wants to take Christa with her.
What if the human Titans in the wall are good and sacrificed themselves to protect the humans and make the wall.
They may have fought on the side of the humans 100 years ago. The prophecy suggests not to wake them as the walls will fall.
Perhaps these could be champion Titans who will assist...
