what if harry starts to realize Hogwarts isn't really the place for him especially for his health what if a certain red haired devil recruited him in place of a certain perverted dragon pawn and showed him how big the mundane and magical world really is and finally what if do to his history and experiences that made him special in the wizard world (Voldemort's soul shard, lily's sacrifice, basilisk blood & phoenix tears, etc.) made him even more unique
Requirements
1. harem the bigger the better ( good old potter charm + dxd logic)
2. harry has to be smart like his mom the reason he doesn't show it at Hogwarts could be for many reasons i would recommend cruddy Dursley upbringing & Ron being a bad influence
3. wizard magic is a middle ground between devil's imagination magic & humans calculation magic with there subconscious handling the calculations & wizard magic giving a boost to both the devil & dxd human magics
4. harry has at least 2 sacred gears 1 he was born with & any others he got from either his mom &/or Voldemort on the Halloween night (I would love to see how he would handle three and how they synergize with each other) with at least one being a variant
5. harry goes to japan with Rias & doesn't return to Hogwarts for schooling
optional
1. harry is the red dragon empower if so i would find it amusing if its the gear he got from his mom's sacrifice
2. the sacred gears harry acquires but one of them has to replace his wand as his magical focuser & amplifier the rest is up to you
3. the effects of having phoenix tears & basilisk venom in his blood during his transformation into a devil from giving him magical eyes with special powers to simply giving a boost to his physical abilities & natural healing its up to you
4. what school year does harry leave Hogwarts i would preferer at least after 2nd year but before the Triwizard tournament ( you could do a thing where harry is forcibly called back & witches & wizards start freaking when there bubbly of being the center of the magical world &/or being the only true magical society pops and they find out there savior/scapegoat has turned into (in there minds) a very dark & evil magical beast this could be an arc of its own and potentially wrap up some loose ends or unfinished business harry has with the wizard world
5. what happened to the soul shard in Harry's head was it expelled when the basilisk bit him was it absorbed by harry/his evil pieces breaking there connection while giving harry a small boost to his abilities and magic is it still stuck in him but is inadvertently torturing/mutating Voldemort do to him being unable to handle Harry's new demonic energies that the connection now has or what alse you can imagine