Multiple crossovers: Battle against the Universe

Hi, I'm starting a fanfic featuring multiple games/animes/original characters, etc. I should tell you guys what it's about: The fic mainly involves multiple characters, all from a different planet to enter a tournament somewhere on planet Earth. Most of them recieved a letter from the King about the tournament and that he didn't trusted it. But as the tournament progresses, some participates turn the tournaments in real battlegrounds, where participates don't only have a chance of losing, but also have a chance to get killed. The main troublemaker in this little drama is Igor, little brother of Rob, who also enters the tournament. They only enter the tournament to show each other once and for all who's the better one. The games/animes I'm gonna involve are:

Kingdom Hearts, Final Fantasy, Original characters, Sonic, Tekken, Digimon

I also have thought out the chapter classification:

Chapter 01: Two brothers: in progression
Chapter 02: Destiny's letter: not written yet
Chapter 03: Xemnas' selection: not written yet
Chapter 04: Sonic speed: not written yet
Chapter 05: The tournament is coming closer: not written yet
Chapter 06: The traitor: not written yet
Chapter 07: New and improved: not written yet
Chapter 08: Forming allies: not written yet
Chapter 09: Final preparations: not written yet
Chapter 10: It's all starting: not written yet
Chapter 11: The first round: not written yet
Chapter 12: The tag has been made!: not written yet
Chapter 13: Sweet motorbike: not written yet
Chapter 14: Igor's frustration: not written yet
Chapter 15: An unbelievable outcome: not written yet
Chapter 16: Underestimated: not written yet
Chapter 17: Speeding Shadow: not written yet
Chapter 18: The Silent Hero: not written yet
Chapter 19: Axel's stops: not written yet
Chapter 20: Igor vs. Riku: not written yet
Chapter 21: The game changes to reality: not written yet
Chapter 22: King's apology: not written yet
Chapter 23: Anger and rage: not written yet
Chapter 24: Igor and Eggman's same game: not written yet
Chapter 25: Danny vs. Igor: not written yet
Chapter 26: Stopping Eggman: not written yet
Chapter 27: One Winged Angel: not written yet
Chapter 28: Last ones standing: not written yet
Chapter 29: Nothing left to fight for?: not written yet
Chapter 30: To end the Battle against the Universe, pt. 1: not written yet
Chapter 30: To end the Battle against the Universe, pt. 2: not written yet