According to Splinter, Mikey actually has the most natural talent for ninjitsu, and could be as good as, if not better, than Leo... that is, if he trained as hard as Leo and didn't goof off so much.
When Leo saves the Ultimate Ninja, Kluh's father said that no one could defeat 3 Levrom Warriors but Leo was fighting 4 of those guys.
How come that judge for the Battle Nexus Tournament is still alive? He was the first person to get sucked into the rift.
Don: And I thought the trophy was bad.
Raph: Ooh, we're never gonna hear the end of this. I'm gonna have to move out.
Raph: (in the opening scene) It may seem like just another day in the Battle Nexus but trust me, this day was gonna be special. I was really looking forward to somebody finally shutting Mikey up about being Battle Nexus champion. But it was starting to look like they were gonna shut Mikey up permenatley.
Mikey: (after the others go away to not train with Mikey) Guys! (sighs)
Leo: I'll help you train.
Mikey: Really, Leo? Aww, thanks.
Leo: I wouldn't start rubbing my shell just yet. We've got a lot of work to do.
Raph: Mikey, you only won the Battle Nexus Tournament because of sheer, dumb, luck. Emphasis on the "dumb" part.
Mikey: Well, if I remember correctly, I beat you fair and square.
Don: Oooh, I don't want to see this.
Raph: (while fighting) You're asking for this Leo.
Don: Big time.
Raph: Give it up Leo. You're going down.
(Leo defeats Raph and Donny)
Raph: Leo. If I have to attack you one more time, I'm going to really attack you.
Don: I'm all for training, but I think you're going overboard.
Leo: I said AGAIN!
Raph: All right, that's it. You and me are having words about this attitude of yours lately.
Mikey: Guys, I don't need to train, I'm the...
Raph: Don't say it Mikey! Don't say it!
Mikey: Battle Nexus Champion!
Mikey: So, who's up for some training?
Donnie and Raph: Not me, I'm going home.
Mikey: Master Splinter, you'll help me train, won't you?
Master Splinter: Oh what's that, training, you say, Michaelangelo? Hmm, I do not know, perhaps there could be television I could be watching, or comic books I could be reading, or pizza I could be eating. Yes, pizza sounds very appetizing right now, with lots of pepperoni and karma.
Villains: Kluh, Kluh's father, Levram warriors
Prologue Narrator: Raphael
Mikey doesn't lose the championship, he ends up defeating Kluh. So maybe Leo was refering more to the fact that Mikey was almost killed.
Due to a bufuddling messing of episode orders, this story has already taken place during "Wing and a Prayer", Leos' cryptic words indicate Mickey loses his championship status in this episode. The true episode number for this is 84.
Kluh is a parody of WWE wrestler Hulk Hogan and Marvel's The Incredible Hulk. Kluh's name backwards is "Hulk," after all.