Rhea was a secondary pallasite of Saint Seiya Omega. He is not a human. As a pallasite, his time control and another powers, depends of his weapon (pawns and arm) and with out it, the distortions made by him disappears.
Like Aphrodite, he is a androgynus man and has female name.
Unlike the other pallasites, Rhea did not has a weapon separate of his body and the only separate weapons are dolls that him controls. His arm has a spear (Gáe Bolg) that perforates everything, like the Excalibur (technically the sword Excalibur cuts everthing [don't perforates] so, is a rival of the Excalibur). The perfect Pawns are wood dolls in human size, that uses axes to attack the enemy.
Rhea in the Japan, saves Hati of the attack of Kouga.
After, Rhea notices about Athena's and Pallas army to Titan.
In the Dvelberg Road, Rhea fights against Shiryu, and Shiryu thinks Rhea will fight against he only using his arms, with no pallasite weapons, so, Shiryu will not uses the Libra Weapons. Rhea's Gáe Bolg don't defeats Shiryu's Excalibur, and because this, Rhea uses his Perfects Pawns and Ryuho (that watch the fight) rebukes Rhea, because he was a cheater. Shiryu allows Rhea perforates him to Ryuho gets angry and brave and gets the Omega Cosmo (only the new generation can despert it, so, Shiryu can't despert), but Rhea his Shiryu in a non-deadly body's place. Ryuho almost desperts the Omega, but his body don't bears. So, Shiryu gets up and tell to Rhea about his sacrifice in allows Rhea hits him, and Rhea perceives that he could be dead if the Gáe Bolg hits his heart, and Shiryu tell he sacrificed himself to helps Ryuho. Shiryu kills Rhea and he tell at last act, that Shiryu is a stupid pather.