Which crossover team-up you're wants to see in fanworks?

This is about unusual crossover team-ups(aka one that never seen alot in even fanworks)
This list is a non-votable list and the content of the list reflects the opinion of its author.

The Top Ten

1 Sora, Riku, Kairi, Donald, and Goofy (Kingdom Hearts); Ash, Misty, Tracey, and Melody (Pokemon Anime); Taichi, Yamato, Sora, Mimi, Koshiro, Joe, Takeru, and Hikari (Digimon); and Robin, Starfire, Beast Boy, and Raven (Teen Titans)

Where the specifics are 8 Original Digidestined are takes 02 forms with
Summer Clothes, KH humans takes KH2 forms, both Ash and Misty are wears
Advanced Generation clothes while Melody(she's from Pokemon 2000) are wears her Street clothes,
the Teen Titans are must from 2003-2006 cartoon, etc.(including even at least some characters are deliberately powered-up than their canon selves by not so random powerups)

2 Anyone from Warhammer 40.000 with whole bunch of Happy Tree Friends, Mario series, Sonic the Hedgehog series, and My Little Pony: Friendship Is Magic main characters
3 Sylar from Heroes TV Series and Flippy from Happy Tree Friends
4 Marco, Tarma, Eri, and Fio from Metal Slug with Any FPS main character

The FPS main characters in Question can be either Doomguy, Master Chief, Nanosuit users, and so on

5 Eduardo Rivera, Kylie Griffin, Garrett Miller, and Roland Jackson from Extreme Ghostbusters with Rick O'Connell, Evelyn O'Connell, Jonathan Carnahan, and Alex O'Connell from The Mummy Trilogy
6 Adam Jensen(Fully Augmented and can add extra tech to his augs) and Avatar Korra(when she can access Super Saiyan Powers through her Avatar state)
7 Grox from Spore and Sermeg Oguma from Metal Slug 3d

Both Grox and Oguma are Anunnaki members

8 Sheldon Jr. Plankton and Computer-Assisted and Biologically Augmented Lifeform

When joining Illuminati, Plankton ditches his Computer Wife in favor of CABAL

9 Lex Luthor, Hannibal Lecter, and Emile Danko

Both Lex Luthor and Hannibal lecter are heavily flanderized where this
Lex Luthor let his hatred toward Superpowered Beings completely
overrides his willingness to join one while This Hannibal Lecter are
completely consumed by his own Carnivorous Cravings(this can't explained
with Zombie Virus infection), plus Emile Danko got overpowered
Nanosuit(this must be cool next-gen Power Armor instead of Spiderman's
Symbiote reskin)

10 Mystery inc from Scooby doo with Team Fortress 2 Mercenaries

Both Mystery inc and TF2 merca has Toonforce Superpowers