I like the idea of Kid bouncing back from his failures to become stronger than ever, but him reading books and studying? Seem incredibly out of character for him. I think the most realistic scenario is him allying with a sect of giants sympathetic to his cause because he is half the reason Big Mom, the terror of Elbaf, has fallen. Also he should reach the next stage of his conqueror’s haki, Killer should also better himself in some way for the comeback to feel real.