Start: I Can Travel Through Time at Will

What if I could travel through any timeline in the world at will to prevent the disaster that was about to happen? If I can travel through any timeline in the world at will to prevent the disaster that is about to happen, then I will be the hero of the world, and I will be the second greatest person in human history. Travel through time and space and try your best to reverse the entire rule, This novel and its characters are purely fictitious. Any similarity is purely coincidental and should not be imitated.