Mirai

Mirai killed her first human at age three. She's willing to do whatever she can to survive, even if it means eliminating all other obstacles. Having been thrown into an elite training camp at 3 she will now compete in a game that only 1 will survive. She was sure she was going to do anything that it will take to survive, but an encounter with an old aquantance might just lead to a change of plans.

Ok so how does that sound I know it's sounds kind of vague right now, but like I said it's just a summary, so chill.