Most of this is Legit but in all Honesty Dumbledore is prob High Mid Class To Entry High Class Max you see wizards already exist in DxD and 95 percent of them only reach Low Class and some of them not even that about 4.5 percent reach Mid Class and the .5 percent? We Got Half Breeds, Legendary Artifacts, Sacred Gears, Reincarnations of Legendary Figures and Legendary Figures Merlin himself in DxD if I'm not mistaken Is Peak-High Class and he's half devil half human (in DxD) on top of being a direct descendant of one of the 4 satans while inventing Human Magic So you see the Problem their? They need something Besides Human Magic to Surpass That High Class Now the Elder Wand? Sure that would probably be equivalent to a mid level sacred Gear like Twilight Healing, and Sword Birth So with that they Might Break into Peak-High Class unless they have something eles helping them and their only making it that far with a Higher End talent and actually putting the work in Merlin is more less a god to the wizard World and if your God is only Peak-High Class how far can you really go?

thou tbh the way you worded it can be easily confused are you saying HP wizards can't break High Class or they all are high class?

Ok so im answering to both your posts here, for HP wizards in my opinion about 80% are low class from which about half are low-low class, that's because they don't go above hogwards educations which is also 1 of the reasons why elevating wizarding world too much in fanfic like that is so bad. They go to equivalent of middle and high school and gain low level skills, they might have mid level magic power because of age but they don't have skills, body, abilities etc to use it and fight on the level of mid class. It's mentioned in og HP that normal wizard even with killing curse can't kill a dragon because of magic resistance. So then you have the "cursed fire" which is like equivalent of normal fire devils use, but you have rituals, alchemy etc that can influence power so yeah wizards don't make mid class normally unless they pursue power, and high class os for monster among their kind like Grindewald and Dumbles and those who dedicate their life to estoric subjects like runes, alchemy etc as they have more potential for in the end. Honestly if they dropped the wands completely then i could imagine some progress in general wizarding society but like this it's not possible. I agree on your comparison of elder wand but you have to remember that many people have sacred gears and don't make it to mid class as they just use it for normal life things and don't pursue power. Potential to become strong dosen't equal being strong and the wand is known for "killing" it's owners, so not being able to kill Dumbles it's possible it's siphoning his life force which would explain his eldery look even though with his magic power he should look much younger as it's a canon fact that powerfull wizards can life much longer like Hogwarts director Dippet had over 300 years. And there is also your mistake with "human" magic because wizards are not human based on DxD lore, humans can't use "wizard" magic as the wizards are born with it. But all humans can learn "human" magic. Also there is no wizards in DxD, there are Magicans but they can't use imagination/emotion based magic, they cast based on calculations, formulas and knowledge and are more like marvel sorcerers where anyone can learn magic but talent is still important. And wizards are more like a subrace of humans or artifical creation. Even DxD wiki dosen't have Merlin's power level, it mentions that his magical knowledge and attitude may be above many of the magic centered gods from different mitologies, also his descendant father of Asia Argento is Maou level just for conparasion and he is defienietly not stronger then Merlin so yeah...

Human magic in DXD should be comparable in form to magecraft in fate. Maybe not 1 to 1 but they both function in a similar manner. Harry Potter magic is like a halfway point to devil magic from human magic.I would probably mention something like Harry potter witchcraft was created during the great war to help humanity survive just like sacred gears. Maybe they were a fallen experiment or something.

I agree, most of the good quality crossovers has wizards as some kind of experiment/mutated humans.