Xbalanque was the first Pyro Archon, who defeated Xiuhcoatl. He may or may not be the “scarlet-eyed” or “crimson-eyed” hero mentioned in various pieces of lore.

Either way, he did probably carve out his own heart to offer it as a sacrifice, as detailed in Blazing Sacrificial Heart. I think this happened after he defeated Xiuhcoatl, and is what led to him becoming the Pyro Archon. I guess that’s kind of speculative, tho.