Rheia's God Power needs a buff.
So, they have reworked Rheia a bit recently, including buffing her myth unit and reworking two of her unique upgrades. However, her god power Traitor is still terrible and it did not receive any changes since launch.
Keep in mind that Traitor is a Heroic Age god power, so it's supposed to be comparable to things like Flaming Weapons, Chaos, Fei Beasts, Frost, Tempest, Ancestors, Curse and Bronze. Yet its effect is very underwhelming and doesn't even work as you think it would.
For example, when you use it on a Champion War Elephant, it reverts to a regular War Elephant without any line upgrades, even if you have Champion Cavalry researched, because Egyptians have different unit line upgrades from Atlanteans. So a 720 HP elephant with 35 Attack becomes a 400 HP Elephant with 25 Attack.
It also doesn't heal the unit to full, so if you convert a unit with half of its HP down, then it keeps its current HP after turning. And it's hard to convert only units with full HP mid-battle.
I really think it should receive the following changes:
1) It heals the turned unit to full. That way, it ensures that it's at least gonna be useful.
2) The units keeps the effects of all of its previous upgrades as well as benefiting from any of your upgrades. This way, a Champion War Elephant wouldn't revert to a regular War Elephant even if you have Champion Cavalry researched. Neither would a Golden Colossus revert to a regular Colossus.
3) Give it additional free charges and/or reduce its recast cost and especially cooldown.
There might be some technical issues preventing it working as it should, which might be a part of the reason why chinese Sages don't convert myth units and instead create a mirror image of them. If that's the case, then maybe Rheia should just get a different God Power.