Hi! I thought of a fun event that could happen sometime! Harry Potter and his crew could visit us! Harry,Ron,and Hermione could give us fun quests or so to help get rid of the evil here! I literally JUST came up with this so I don't have all the details yet but let me know what you guys think! Thanks!
KI would have to buy rights from WB or JK Rowling to use the characters' likeness, that probably wouldn't be feasible for them.
Nick Jonas and Selena Gomez can be found in game for contributing their talents, I'm unsure of what the HP characters can bring, although it would be cool to see a cameo or Easter egg (Game of Thrones references abundant in parts of Avalon)
could be fun. KI would just have to buy the rights to put Harry Potter in a video game from whichever company, or person, who currently owns those rights. Assuming that entity is willing to sell those rights to KI. Then of course KI has to make the character models and get passable voices for those characters, before those rights revert to Ms. Rowling, or some publisher.
I think the cheapest thing to do would be to add in the brooms from the stories as mounts. This way, you dont have to pay as much because they're not people (though I know nothing about the legalities). Id love to ride a firebolt