The Battle Nexus was governed by a mystical figure known only as the Daimyo, who presided over the matches of the tournament and maintained the peace of his realm using the War Staff of Ultimate Power. Though the Daimyo had final say over who could compete in the tournament (and, more generally, on any other rulings) however, the individual matches were usually refereed by his servant, an ethereal being Gyoji.
The Battle Nexus was capable of supporting lifeforms from various atmospheric conditions, including Traximus, a member of the nitrogen and sulfur-breathing Triceraton race, who was able to move about and fight comfortably without the aid of a breathing apparatus.
The Ninja Turtles entered the Battle Nexus Tournament having followed Splinter through an interdimensional gateway. Once there, they learned that Splinter was in fact the previous champion of the competition, as had his own master Hamato Yoshi before him. While competing, the Turtles had to unfoil a plot conceived by theUltimate Ninja - the son of the Daimyo - and Splinter's old rival, the evil dragon named Drako. The two had attempted to steal the Daimyo's staff and using it to rule the galaxies. Eventually, however, they were defeated. (The Big Brawl)
Later, Leonardo and Miyamoto Usagi return to the Battle Nexus after the fused "Ultimate Drako" scatters the Turtles across time and space. There, they must fight the two villains once again, but thanks to the Time Scepter of Lord Simultaneous, they prevailed. (The Real World, Part 2)
- Hamato Yoshi (Former champion) (1986)
- The Shredder (Former champion. 3 statues of him in his Feudal era armor are seen, indicating that he had fought in the Battle Nexus too.)
- Ninja Tribunal (Former champions)
- Drako (Former champion, won before Splinter) (1998)
- Splinter (Former champion, won before Michelangelo) (2001)
- Michelangelo (Current champion. Though the final round was interrupted, official victory status was awarded to Michelangelo. In a later episode, an official Battle Nexus championship rematch was replayed and Michelangelo defeated his opponent Kluh again, this time fair and square. He also got a medal this time around for his character in battle.)
All tournament champions have a statue of themselves erected in the Hall of Champions.
Participants in the Latest Tournament
Note: This is the tournament shown in "Big Brawl".
- Splinter: Defeated Wolf in round one, and lost in round two by forfeit to his son, Michelangelo.
- Leonardo: Defeated Kwan in round one, but was struck by poison dart in round two while fighting Usagi and had to leave the tournament. For some strange reason, there was no rematch between him and Usagi after he was nursed back to health.
- Raphael: Defeated Rings in round one, defeated Traximus in round two, and lost to Michelangelo in round three.
- Donatello: Lost in round one to Staff.
- Michelangelo: Defeated Tjaluk in round one, defeated Splinter by forfeit in round two, defeated Raphael in round three, defeated La in round four, and defeated Kluh to win the tournament in the final round. Due to interference in the final round, a rematch was called, which Michelangelo won.
- Miyamoto Usagi: Defeated Sickle in round one, but left the tournament in round two after his opponent Leonardo got hit by a poison dart.
- Gen: Defeated unknown Clawed contestant in round one, defeated unknown Octopus contestant in round two, got free pass in round three, and lost to Kluh in round four.
- Kluh: Defeated Fantasy Warrior in round one, defeated Gorath in round two, defeated Zat in round three, defeated Gen in round four, and lost to Michelangelo in final and rematch round.
- Traximus: Defeated Hook in round one and lost in round two to Raphael.
- Dieskrad: Defeated Albert in round one, defeated Staff in round two, and lost in round three to La.
- Ia: Not seen in round one, defeated Krall in round two, defeated Dieskrad in round three, and lost in round four to Michaelangelo.
- Zat/Butterfly swords: Not seen in round one, defeated Fly in round two, and lost in round three to Kluh.
- D'Jinn: Lost to Splinter in preliminary round.
- Two heads: Lost to Octopus Contestant in round one.
- Lajatang: Lost to Krall in round one.
- Kwan: Lost to Leonardo in round one.
- Hook: Lost to Traximus in round one.
- Albert: Lost to Dieskrad in round one.
- Fly: Defeated unknown Jewel Gauntlet contestant in round one and lost to Zat in round two.
- Sickle: Lost to Usagi in round one.
- Rings: Lost to Raphael in round one.
- Octopus Contestant: Defeated Two heads in round one and lost to Gen in round two.
- Staff: Defeated Donatello in round one.
- Wolf: Lost to Splinter in round one.
- Tjaluk of Setia hati terate: Lost to Michaelangelo in round one.
- Krall: Defeated Lajatang in round one.
- Tiger: Seen among contestants but not fighting.
- Sjang Sutai: Lost to Gorath in round one.
- Gorath: Defeated Sjang Sutai in round one but lost to Kluh in round two.
- Fantasy Warrior: Lost to Kluh in round one.
- Jewel Gauntlet Contestant: Lost to Fly in round one.
- Clawed Contestant: Lost to Gen in round one.