Harry Potter/Xiaolin Showdown crossover idea
After regaining her body, albeit in a less powerful form, Wuya decides that in order to do better in battle to collect the Shen Gong Wu she requires an apprentice to teach haylin magic too. So where does she go? No other than Hogwarts! Using unknown Haylin magic she manages to trick the school and staff into believing she is a normal, but powerful, witch. Taking the position of DADA teacher in Harry's 2nd year, she soon decides upon the young Potter to become her apprentice. Would include a somewhat-evil!Harry, HarryXWuya (with her being the dominant one in the relationship until Harry matured slightly into a more commanding boy/man), HarryXHarem (As all evil overlords deserve such a thing), competent!Harry, and possibly some non-con stuff. This fic would have to be done off of because of many of these elements.
Random ideas for this set up:
Wuya and Harry having private lessons where Wuya uses the alone time for 'pleasure' as well as teaching, such as having Harry pamper her feet or just eat her out.
Harry using Jack Spicer in a support role to create robots just to distract the monks so he can grab Shen Gong Wu.
Harry getting along with Chase Young's cats and maybe spending some time looking after them. Would not necessarily make him and Chase friends, just acquaintances.
Wuya having 'naughty' Xiaolin Showdowns to teach Harry about how they work and to give them a chance for some fun.
Harry using the Woozy Shooter, the Hogwarts ventilation/piping system, and a recording of hiss voice to leave the whole school vulnerable to his suggestions with a good chance to use it for sex purposes.