I'll become the hero

"we have a deal" Allen is a hunter that experienced the end and the only one that survive being face to face with it. Millions of giant raise from the ground When all other creatures vanish. Experiencing death for the first, allen woke up at the time when he was being recruited to become a hunter, eighteen years before the end. 'did I came back in time?, he thought unable to clearly remember the past life he already experienced.