Yesnth
here is an idea for his third technique. If the Mc was smart he could've become the strongest being in the jujutsu verse from day 1. There is a stand [Wonder of U] from Jojo's Bizarre Adventure:Wonder of U has the ability to manipulate the flow of calamity, a universal force. Let's say a person is trying to attack or pursue the user in any shape or form (even mentioning his name or trying to find out where he is) then that person will be attacked/followed by the flow of calamity(universe) and therefore calamities will start happening to them. Anything from an object colliding with that persons legs that normally wouldn't do nothing now will rip that persons legs of, to dropping an asteroid on them to getting cancer and so on. Calamities will continue to occur until that person is dead. Since you already plan on the Mc being op, this is an interesting way to do it.