Undying

"For there is no such thing as certainty, and yet more truth in lying / When one’s soul is given to the ageless grasp of the Undying. "

- Dreams of a Colossus, author unknown

The Undying are the first sentients of the world of Elemnakos, and bear a complete connection to the raw magic of the world. However, as life developed, Chaos began to muddy this connection, and the Undying, who had no defense against such an infection, were slowly driven mad by this taint.

These corrupted gods of gods were chained down by the ascendants of the Elder Lines whenever they broke free and sought to twist reality to match the chaos inside them. The last and most final chaining was led by Inyaha, Sunlord, who brought down mountains and seas atop them, trusting the immense weight and pressure to contain that which could not die.

In Modern Elemnakos
In the modern day, one of the Undying has reawakened in its horrific prison of constricting caverns deep beneath the citadel now called Cloud Mountain. Dashiin ai-Yakur and Andraste bargained with it, and hid its awakening from the gods above in exchange for unknown boons, among which was the presence of the Serpentguard.

That particular Undying is theorized to be the cause of Serha Yakur's resurrection.