expand_less The Rha pantheon has a few things going on.  Not only is it primarily inspired by Egyptian mythology, it's also the ancestral home of Dragons and the seat of their power.  Given that this is a high fantasy world with a number of diverse races and cultures, we would expect that aspect to be especially relevant here given the diversity of Egyptian gods.  The hierarchy and relationships between these groups should be interesting to develop, particularly the extremes such as slavery.  In one draft I referred to this as the [[Dominion of Dragons]], with sentient bird-like lizards (think D&D's kobolds) serving as slaves and primitive worshipers of those terrible lizards. Eventually they rebelled and evolved into an avian race known as the [[Sauren]], creating the [[Free Cities of Khamat-Hulrha]] after the [[First Sparks of Revolution]].  During the modern era, they revere the phoenix as a symbol of their rebirth and as an opposing force to the dragons.  In that spirit they've revived the old religions, adapting them to suit their current outlook.   Notably there was the [[Floating City of Urypt]], which traveled widely and was known to many ancient cultures.  I imagined it as a mix of the Rha and Sace peoples before the fall of their ancient societies.  There were also a few passing references to the [[Ancient Hulrha]] and [[Ancient Urypt]] languages.
The above was my working draft for previous games, but nothing is really set in stone (except perhaps the name of Urypt, which serves as an important plot point).  Compelling conflicts setting fire against fire are difficult to conceive, but I imagine we can come up with more creative solutions.  Assuming that we want to stick with the Egyptian inspiration, I think the following are among the most important gods to represent: Amun/Ra, Horus, Set, Osiris, and Isis.  Given that there are literally thousands of Egyptian gods, we will need to cut our list down to the essentials, possibly merging historic gods where we can.  Since Amun and Ra were historically merged, that seems like a good place to start.  They're also easy to place as they match many aspects of Rha as gods of the sun and leadership (I actually named the color Rha in anticipation of placing the god here, so the two concepts were somewhat co-developed).  So let's say that Amun-Ra is our inspiration for the Rha Ohm god.  Horus was a god of kingship and the sky, but he's most known for myths of avenging his father Osiris against his rival, Set.  Vengeance or hate naturally fit into Rha Sace, so let's place him there for now.  Set was the protector of Ra, known primarily for keeping the dark serpent Apep at bay and his rivalry with Horus.  He seems to fit best into Rha Dau, mostly due to his brawn and combative nature (incidentally the grab keyword in Rha Dau counters the Swim keyword in Ela Biz, so a god in those colors defeating a swimming monster makes gameplay sense).  Rha Dau and Rha Sace seem like natural rivals.  That leaves us with the Rha Ela god.  I'm least sure of this, so there are a few options as I see it.  We could merge Osirs and the Rha Ohm god (Amun-Ra) to make them the father of the Rha Sace god (Horus).  Then we could make Isis the Rha Ela goddesss.  Together these four represent something of a cohesive whole, telling a story of death, revenge, rivalry, and ultimately triumph and the right to rule.  Alternatively, we could make the Rha Ela god based on Hapi, the Egyptian god of the Nile.  This fits since Ela is one of the colors of water, which would be highly valued in the otherwise firey Rha pantehon.
Upon further consideration, Ra was also merged with Horus in some versions of the myths.  Perhaps we could represent both Ra and Horus in the Rha Ohm colors as two different versions of the same deity?  Another consideration is adjacent pantheons.  We know that the Rha Sace god is both love and hate, so ideally we'd pick one god or goddess to represent both sides of that coin, with love being emphasized in the Sace pantheon.  Isis might fit best here, leaving Osiris as the Rha Ela deity.  Then again, there's nothing stopping us from switching the gender of Horus to fit both the Mesopotamian/Persian inspired goddess of love, as well as a new Egyptian inspired goddess of vengeance.  Set was eventually demonized by the Egyptians and the Dau pantheon is a monstrous one, so likely we can keep him on Rha Dau.  There are also many other important Egyptian deities like Anubis or Thoth, especially when we consider the origin myth itself.  Truenaming magic used by Ra and Isis would likely be Rha Sace Quae colored (Rha for names, Sace for Magic, and Quae for secret knowledge).  Likely the keeper of these names would be the Rha Quae deity, so there's something of a story there between the Rha Quae and Rha Sace deities.