Had an idea for Hoopa. After the MC has answered all the questions of, Whos that Pokémon, using all senses but sight she would try to go back on the deal, since her unbound form has dark attribute she in her weakened form would still try to get out of the deal by summoning multiple Legendary Pokémon of their dimension. She would not know what has happened to the legends and just think they will tear him apart but when she sees them pregnant Hoopa says "What the fuck happened to you all?" and their response would be "the same that is about to happen to you." The MC would SNEAK UP behind her and bear hug her in a sneak attack while land a big kiss right on her which would be super effective since she is both psychic and a ghost type in her confined form. Once she knows she could get pregnant she thinks of all the mischief she can do if there were more of her and then agrees to join his harem.
A side event for her could be since she has a secret treasure somewhere she takes the MC to get it and its a cracked ring like the one she uses. She made it to temporarily go into her unbound form for a few minutes but after one use it cracked and will be destroyed if she uses it again. The MC can turn his dick into a confined Hoopa dick and puts the ring on that which turns it into three unbound Hoopa dicks (since more arms are added in unbound state) temporarily that float in air that MC can control and can do her mouth, ass, and pussie at same time. Since the ring is only on the dick it wont crack as fast so lasts until he gets back on the boat.