Actually, I've played through the game about seven or so times this summer. I have almost no trouble with the rest of the Fighting Ring challenges, but 15 just seems like a bad joke. Two Skinny Asses and an Elite Lady with a whip on level Die and almost no health for anyone. I usually manage to beat one of the Skinny Asses, but the whip always gets me and there goes the only bit of life I'm given.
I'm able to dodge Elvis' jump most of the time, because I see it coming somehow. I suck at dodging Belze's attacks. x_x
Oh, okay. I thought that somehow you were new to the game or something from that previous post. Elvis in all of his forms was the only lv.Die boss that I had the hardest time with consistently beating. Belze wasn't so bad, imo. Almost all of his attacks could be simply high dodged. I'm blanking on her name, but the demon form of the chick was my favorite to fight, outside of the battles against devil hand and double god hand.
I remember that mission 15 though. It is a bitch to do. I ended up beating it by immediately dive kicking the left guy, then wasting the whip chick second and the other lanky guy last. It took me a lot of tries to beat it, but I managed to do it the chapter that it was unlocked somehow.