Episode 15

A Hero's Proof (ヒーローの資格)  is the fifteenth episode of the JoJo's Bizarre Adventure anime. It is also the sixth episode of Battle Tendency. It covers Chapter 66 through Chapter 70 of the manga.

Summary
Caesar engages Wamuu in battle for killing Mark, using his Bubble Launcher technique to surround the Pillar Man in Ripple infused bubbles. Once Wamuu realizes he is facing a Ripple user he uses his mysterious headgear to unleash a wind that bursts all of the bubbles. However, his attack is not yet over, as the movement created hundreds of miniature tornadoes that shred Caesar's skin, leaving him incapacitated and temporarily blinded in one eye. His boasts that he need not see to fight the Pillar Men amuses them, as Ripple users of two millennia past said the same things to them before they killed them. Kars and Esidisi head to the surface, allowing Wamuu to finish Caesar off as the only Ripple user left, only for Joseph to make himself known, proclaiming that he has developed his own special Ripple technique using a pair of clackers that he channels the Ripple through. Wamuu allows him to fight, slicing through his wrist to the artery to make the battle last only a minute His first attack, the Ripple Clacker Volley, appears to miss its mark, embedding a steel ball into a pillar behind Wamuu, but this is all part of a ploy to engage his other technique, Clacker Boomerang, where he has thrown another Ripple empowered pair of clackers behind Wamuu, catching onto the original clacker, and actually landing a blow on Wamuu. Angered, Wamuu allows Joseph to continue to strike him with the clackers while he prepares his counter, the Holy Sandstorm. Wamuu claims his attack has been hindered by his eyesight and a pillar blocking Joseph, but Joseph is left barely alive. Playing dead, Joseph tries to run away, seemingly stranding Caesar and Speedwagon, but it is all a ploy to lure Wamuu away before he can kill the others. Joseph takes Wamuu on a mine cart ride through the ruins, intending to use a stick of dynamite to destroy him, but Wamuu anticipates these events and sends them flying, intending to kill Joseph for his insolence. However, Joseph proclaims that he could possibly be even stronger in a month's time, intriguing Wamuu, who decides to let Joseph live to get stronger with the Ripple in only a month, implanting a "Wedding Ring" in Joseph's body around his aorta that will release a deadly poison in 33 days' time, unless Joseph can get the antidote held in his lip piercing by killing him in battle. Any attempt to forcefully remove the ring will also release the poison. Esidisi, who has come to see what has been holding Wamuu up, also decides to enter in on the wager (after consuming the stick of dynamite before it explodes), implanting another poison-filled ring around Joseph's windpipe, with the antidote in his own nose piercing. Kars, however, passes on the game, and the Pillar Men leave in search of the Red Stone of Aja, and Joseph passes out from the strain of the battle. Caesar, who has been watching the whole time, realizes Joseph's resolve and promises to also get stronger with him.