Set /sɛt/ or Seth /sɛθ/ (Egyptian: stẖ;[a]) is a god of deserts, storms, disorder, violence, and foreigners in ancient Egyptian religion.1 In Ancient Greek, the god's name is given as Sēth (Σήθ). Set had a positive role where he accompanies Ra on his solar boat to repel Apep, the serpent of Chaos.1 Set had a vital role as a reconciled combatant.1 He was lord of the red (desert) land, where he was the balance to Horus' role as lord of the black (soil) land.1 Set
Ka, also (alternatively) Sekhen,1 was a Predynastic pharaoh of Upper Egypt belonging to Dynasty 0. He probably reigned during the first half of the 32nd century BC. The length of his reign is unknown. Sekhen
Now in legend, Horus, is supposed to be Sets nephew. It just so happens that Horus-Aha is predecessed by Narmer, who is predecessed by Sekhen.
Predecessor Ka (Sekhen) Successor Hor-Aha Narmer
So we have a legend which states that Set went to war with his nephew Horus, over kingship of Egypt.
We also have a real pre-dynastic pharoah, from dynasty 0, named Sekhen, who appears to have a nephew or relation named Horus-Aha.
So could this account for Sekhen being Set? And are there any ancient sources which describe Set as a mortal?