Super Villians!
One of my favorite arcs in fantasy stories (comics, movies, books) is when two unrelated badasses, who are often previously developed as the mysterious bad guy, become aware of each other. It’s so great because from the protaganists point of view, you become amazed at their individual powers, not really knowing their limits, just that the hero has to dig deeper than he ever has before to defeat them. So, it’s really unknown who is stronger when they match up against one another. And, if they both are “evil”, the author will often soften up one side, so it is easy to root for one guy. But it’s even better when he just lets them duke it out and you there’s no good guy always wins type of shit going on. It’s just a display of who’s a bigger badass.
This doesn’t even have to relate to supernatural shit. It can be two guys you meet in a story who are both wise sages or two leaders of random armies or just two badasses who face off. They don’t even have to fight, it’s just sometimes mind blowing to see those interactions.
You know, I have no idea what I’m talking about because now that I think of it, I can only think of one example, in the anime Rurouni Kenshin and I sure as hell don’t remember those names.