So lets talk about "Unkillable" Champions in Lore

You know, Champions where a nation fears their pressence alone. There are a few "Worldenders" I can think of, Lorewise. The Darkins, Aatrox and Rhast specifically, Mordekaiser, perhaps even Pyke. There are a few others I might add, like olaf, Sejuanni, Nasus, etc. However, for some reason, they don't scream as big a threat as someone like Morde.

Now why did I add pyke in this list? For the reason he can't die, and puts an entire nation on the edge of their seat. He can't be stopped, and he can't be overpowered. Champions such as Nasus, Olaf, Sejuanni, Xin zhao, Panth, Darius/Garen all have their own roadblocks. They may never stop trying, but they are susceptible to failure (especially pantheon). That isn't to say they aren't strong, but they can be stopped.

But Darkins, Morde, and Pyke? You can't stop them, can't overpower them, can't run from them, etc. Sure, pyke might be on the lower end of the spectrum here, but Aatrox, Rhast, and Morde are most certaintly top dogs here.

So what happens when these 3 run into each other in the Lore? Like what would happen?