All right, so recently Tommy Andreasen revealed that Eris is possibly the reincarnation of Florax, Flinx's mother, and one of eight Phoenix who participated in the failed Great Illumination. This seems to indicate that all of other Phoenix were killed and forced to reincarnate as a result, instead of going to the Mother Sun; Possibly so they could amend their mistakes by either redoing the Great Illumination, or ensuring its success.
Thus, I began to wonder- Who ARE the other reincarnated Phoenix? We know there are seven left to figure out, and we know they can't be any of the other eight heroes, since Fluminox never recognized them. Likewise, they can't be Crawlers, as those were beings unrelated with Chi, so it'd make little sense for the Phoenix, beings all about Chi, to be reborn as one. They can't be Ice Hunters, as they were all alive when those Phoenixes died, and it can't be any other members of the Phoenix Tribe, no Tigers, and Lundor and Li'Ella are also excluded.
By looking at the evidence, I've ultimately scanned over the clues, searching the rest of the cast to see who might be a reincarnated Phoenix... and after a while, I've got a few possible candidates;
-Lagravis
-Lavertus
-Crominus
-Rinona
My reasoning? Well, let's start off with this fact;
When people used Fire Chi, they just glow red-orange, and that's it. Oddly enough, the main eight don their Fire Armor, but why would this happen? Well, consider the very Phoenix-esque armor designs, and the fact that those eight heroes are destined to wear the Fire Harnesses...
Get where I'm going here? The only ones who get the Fire Armor are the ones meant to wield the Fire Harnesses, which would ALSO apply to the reincarnated Phoenix souls...
Likewise, Lagravis is worthy enough to wield the Triple Chi Armor (whereas Cragger and Worriz, two non-Phoenix souls, aren't), Rinona is oddly enough not affected by the Rhino Legend Beast's power, and while we are told ALL females are smarter, it still seems a bit odd she's singled out... unless she DIDN'T have a Rhino soul! Likewise, she, Lagravis, Lavertus, and Crominus all have fire armor despite not being meant to wear the Fire Harnesses... that is, unless they weren't meant to in THIS life!
My theory- Those destined to wield the Fire Harnesses are given the Fire Armor, and likewise, Lagravis, Lavertus, Crominus, and Rinona are reincarnated Phoenix souls, hence why they have the armor; THEY'RE part of the original, chosen batch who failed! Worth noting, also, is that those three are all wise, good-natured people.
With this in mind, that means we have...
-Fluminox
-Florax (Eris)
-Lagravis
-Lavertus
-Crominus
-Rinona
That leaves three other souls unconfirmed. The only other candidate I can think of at the moment is Crokenburg, since he's the only non-hero or theorized Phoenix reincarnation to have the printed, Fire Chi piece, though this might simply be because of the presence of a harness, as his armor underneath is generic crocodile clothing.