Dagon was a Demon Lord who made a pact with Lucifer in return for having the realm of Eden for his own personal use.
Dagon was one of several Demon Lords that Lucifer made a pact with following the war on Eden. The bargain was simple, Dagon's soul upon his death in exchange for Eden to have as his own.
Dagon set to work, bolstering his forces to begin the cleansing of Eden. Corrupting the holy water in the realm, he planned on washing away every living thing in order to create a clean slate upon which he would build his new kingdom.
Dagon was in the middle of starting a ritual to start his great cleansing until his Stormcaller shamans were killed by the Horsemen Strife and War. After the Horsemen managed to kill his Stormcaller and sealed the portal to Eden, the Horsemen confronted Dagon directly after slaughtering his forces in their way. Dagon was killed after trying to drown the two Horseman.
Dagon was a giant demon that proved formidable in waters as an aquatic type with large tentacles to entrap his enemies and he could flood entire realms after managing to finish his cleansing rituals. He was a potent Demon Lord with formidable control over water, wind, and air to the point he could conjure storms at will and floods to wash away his enemies. He could also control lightning and generate energy to strike opponents from a distance.