Percy

Percy is the current reincarnation of Thanatos. 

Percy in his youth had an affinity for magic, and at a young age was sent to the mage island to perfect his abilities. While there, he learned about the holders of the god's powers, such as himself. 

Harpies do not have a naturally long lifespan, but because of his affinity for magic and status as the current reincarnation of Thanatos, he has been able to extend his lifespan over centuries. 

While studying The Silent Expanse, he met Damain, who, at the time, had unknowingly easily harnessed the powers of The Nexus. With the Nexus, he was able to find the Olmic city, and would frequently visit on his own. Percy met him there, surprised to find another with such apt abilities with the Nexus. They bonded, and soon became engaged, despite being complete opposites. 

Percy, much like his spouse, Damian, has developed unique physical  traits associated with residents of The Void & The Silent Expanse.  This is because of tampering with Void energy, which both have done.  Percy more than Damian.

Percy studies the Anemoi split, and had known the previous reincarnates. The previous Notos, before Tucker, was eccentric.  He was also a well-regarded scholar like Percy, and the two had developed a plan for harnessing the powers of the Anemoi, to open a portal of unimaginable power. 

The previous Notos died in the first attempt, causing Percy to seek out the new Incarnate. After almost 30 years of searching, he found Tucker, and convinced him to continue their research.