Honestly I was pondering about who would win in a duel, a Mashle Wizard or a Harry Potter wizard.
Some might say "Of course a Mashle Wizard will win!" and I can understand why, considering how broken some spells are over there, but in terms of the 3 forbidden spells, I think they beat Mashle. I mean, a spell that instantly kills your opponent, torture him in the most painful way possible and literal mind control is kind of insane, considering the other spells around. But on the other hand, personal spells like Graviole or the puppet thing is also extremely overpowered.
Also their worlds are pretty similar (totally by pure coincidence i'm sure). So, imagine a Mashle wizard at hogwarts or the reverse. It would make for a pretty interesting story I'd say.
P.S I've seen someone make a meme where the Raya Lucaria academy joins the triwizard tournament and seeing them summon Meteorites and using the comet spell, pretty funny honestly. Might also be a good idea, but I have not yet finished elden ring, so I have little to add.