Eternal Rebirth Flame & Chen He!
Endless Crimson Flame was the name of the Higher Existences faction led by Eternal Phoenix, and usually a faction's name was based on something important either solely to the leader or to everyone who was part of it in general.
Unlike the other factions, Endless Crimson Flame had the fewest members overall. In fact, all of them added together probably amounted to no more than a few million; probably just scraping ten million in total.
However, being fewer in number did not mean that other factions dared to underestimate them. After all, even the dragon faction that was one of the most terrifying of the eight considered them extremely frightening enemies to face despite the fact that they verbally disdained them and hated them to the bone for some reason.