Xarthryss

Xarthryss, the Eye Tyrant, was a Beholder of considerable power, a member of the Pact of Iron, and the ruler of the Scourshores and the Rathys Jungle. He was self-obsessed and paranoid, even for one of his kind, building the city of Vyzanth in his image, with thousands of statues of himself constructed all across the city, and mighty monuments, built on the backs and the bones of slaves, glorifying him and his honor. Xarthryss gained immortality through the power of a Beholder's natural reality manipulation, the previous "Xarthryss" having drempt up a more powerful, immortal version of himself, only to be slain by it.
In the Age of Iron, the Scourshores were known as the Verdant Shores, and were lush and filled with life. When the Order of the Golden Rose conquired and sacked his Monument City of Vyzanth, Xarthryss retreated to the Verdant Shores. Increasingly paranoid about infiltration and betrayal, he began killing his followers, then the animals, then the plants, using his powers to scour every touch of life from the islands. Seemingly contained, the Order left him to his islands for a time so they could focus on Masalisk, but eventually landed at the site that is now known as Voruna, forcing a final clash with the insane aberration.