Ulgard Greenblood

Ulgard Greenblood was a legendary figure; first Chieftain of the Jorgun, then the Arch-Demon of the Sea, then the central figure of worship for the religion of Navicism, until finally he was slain.
Greenblood was originally from Tyrrus, from the Stormcliffs and the Jorgun tribe. He gathered many longships and tried to cross the Storm Barrier, but was attacked by a kraken and his ship was sunk. However, as he died, he sunk through the sea into a deep trench connected to the Abyss. This area is now called Greenblood's Trench. An unknown Dark God reached out from the Abyss, and gave Ulgard the power to return to life as an Ascended.
Upon returning, Greenblood washed up on the shores of Isla Calamar, near a small town called Calavierus. He quickly took control of the area, and under his leadership the Calamarans managed to take over most of the Shattered Sea.
Greenblood held power over life and death at sea, and whenever he died he was able to come back, slightly less intact. The souls of most who died at sea were under his power to command, and he also controlled vast armies of sea demons.
After dying many times, Greenblood eventually lost his body entirely. His influence was still able to be felt across the Shattered Sea, he could still corrupt humans, and he could still command his many armies of undead and demons, but he could not physically fight his enemies.
In 20.15, a group of Calamarans accidentally made their way to the Wandering Isle, after the portal was opened by Antonio Venceslas. While on the Isle, they were able to return Greenblood to his body.
About a year later, Emilio Ventura, Kagami Nakamura, and Vanessa Fang faced Greenblood when he returned to the world, and managed to slay him with Godsever.