It was the "Master of Water", Molander, who first fell prey to this, believing that by experimenting with the Undead and other forms of life he could learn about how water gave rise and sustenance to life.
It was he who corrupted the "Master of Fire", Ziraphelis, who became possessed by a Dire Spectre and killed Molander after he was of no more use to him. The other two Masters, Caltarelair of Earth and Remishaz of Air, were distracted from this after Ziraphelis - having become Master of All Elements - raised a Vortex of Discord to divide them, and they killed each other. However, all three of the slain Masters continued to haunt their respective domains.
Caltarelair and Remishaz would only be released from their spiritual bondage when the Vortex was destroyed by a fisherman hero who had journeyed to the island in search of answers as to why the seas, until then kept under the control of the Masters, had become dangerous again. Molander was banished by the fisherman in combat, whilst Ziraphelis was killed and the Dire Spectre cast back into the deepest ether from whence it came.