Geo_Ruler
okay so i got curious who actually cursed gotham and its a immortal sorcerer named Dr.Gotham i like to think he is hiding under batmans nose by hiding right under his house and the batcave cause if i wanted to hide thats what i do hide right under my foes and watch them run around like their heads are cut off for my amusment, especially magic people are very vendictive and arrogant so they are kinda predictable
I would like to see the protagonist choose a Demon Slayer character to learn the breathing technique. It's not a strong world but the breathing technique is viable to increase the power of the Batfamily, including the technique in the 'secrets' so you don't worry too. With his intelligence, he could improve the breathing technique into a universal one without the need to choose between different breathing techniques. It would be good if Tanjiro was the chosen character, because he is a very emotional character, he has a lot of kindness even towards demons and the protagonist is also kind in his own ways. Regarding physical techniques, he could even choose the universe of Baki, Kengan Ashura, Street Fighter, The King of Fighters, Tekken or Mortal Kombat. These universes are not extremely powerful besides the gods(?) from Mortal Kombat and Orochi from TKF from what I remember. However, the fighting techniques of these worlds are very incredible. I also remember that the protagonist and ES talked about choosing a One Piece character because of the hakis, it could also include the techniques of the six marine styles, which is a good complement to improving physical fitness as a whole.