InGlorious
I really hope MCU isn't the world right after Harry Potter, because that would completely invalidate any and all worlds that come after. To deal with MCU the MC would have to become so strong that any other world you'll have him go to afterwards will be like an elephant dealing with ants, so I hope you're prepared for finding another way to keep the story interesting in that case.
give Reo's family the bloodline of Celestial immortals, but make them invulnerable. can't be killed by The Horde insects, Beyonders or any others. in their Celestials completed metalic forms they average 2000 feet tall and 260 tons( marvel Celestials wiki ). usually the family looks humanoid and you can customize their gifts.
going along the line of 'it ended in the same way I read in the story' is a really bad way of telling a story. Not everybody reading fanfiction will have even read all the Harry Potters books or even remember everything that happened. Do something along the lines of 'and just like in the books, Cedric managed to get his egg by distracting the dragon with a conjured goat' or something.