|Fon vs Mammon|
Fong VS. Māmon
|Arc||The Curse of the Rainbow Arc|
|Volume||The Eighth Baby Arrives!|
Hibari Kyoya vs. Xanxus
Mammon further explains the details behind Viper Mirage R. Belphegor is impressed and pats Mammon on the head, but comments that he is still short. Mammon cautions Belphegor from touching him, and explains that Hyper Mirage R doesn't only apply to the combatants: the technique is applied to everyone on the floor. Belphegor protests, but Mammon calmly states that it is fair, since it applies to him as well, and he adds that the condition he set was fairly reasonable. Fon, lightly smiling, declares that he and Hibari won't lose confidence-wise. Squalo mentally comments that it will be interesting to see Hibari getting beaten up by Xanxus, but also adds that, no doubt, the highlight of the match will be the battle between the two Arcobaleno.
Fon confirms with Mammon that he just said that illusions were superior to martial arts. Mammon asks if he had a problem, but Fon denies it, stating that Mammon's claim greatly intrigued him. Fon wonders aloud whether his martial arts were superior or inferior, but that causes Mammon to disappear, who states to Fon that his positive thinking was what he hated about him. Fon in turn also begins to disappear, chiding Mammon for saying so. Squalo explains to Belphegor that Mammon had cast an illusion on himself and Fon to put them in a mental battlefield. Meanwhile, Hibari charges at Xanxus, and they clash.
In Mammon's illusion, which conjured the Earth as the battle field with the stars and planets in the background, Fon compliments Mammon on his ability. Mammon disregards this and tells Fon that as his mind was in the illusion, and that he could thus control his movements. Mammon unleashes various vines at Fon, but Fon breaks free of the paralysis by shedding a seemingly outer core of himself. Mammon expresses his amazement and shock, and Fon explains that in reality, he had practiced techniques to release himself from paralysis, so in his mind, the thought of being paralyzed didn't exist. Mammon is greatly angered and unleashes the strongest of his illusions, Uroboros, a large eel-like creature without eyes but with sharp teeth. However, Fon easily shatters Uroboros with his martial art techniques. Fon explains to Mammon that he could defeat Uroboros because he'd faced a similar illusion before, to train the level of his mind. Mammon, shocked, wonders what kind of training Fon had been through previously.
Suddenly, the illusion begins to dissolve as Mammon is cut by Fon, and Fon comments that it wasn't looking good for Mammon, as he had been damaged by his Viper Mirage R rule: that anyone doubting in their victory would self-destruct. Fon yells at Mammon to stop thinking about what he's thinking about, as he would continue to bleed, but Mammon coughs blood up and continues to bleed profusely. Fon prepares to kick Mammon into unconsciousness so he wouldn't bleed, but suddenly he loses his un-cursed form and turns into an Arcobaleno once more. Hibari watches grimly and Xanxus with a smile, as Mammon exclaims in relief. Mammon shouts in triumph at Fon, stating that even if he won their match, he would win the Representative Battle of the Rainbow. Fon, despairing, begins to self-destruct. Mammon and Xanxus then begin a joint attack on Hibari, Mammon freezing Hibari in ice with an illusion, sealing him in a position with his arms bound together and held out. Xanxus fires a shot from his X-Guns, but Dino arrives just in time and stops Mammon's illusion by pulling his hand with his bullwhip, allowing Hibari to escape. Dino tells Mammon and Xanxus not to dare to attack his pupil.