Dreadlord Zyrbryxion, The Bringer Of Eternal Night

Zyrbryxion was a black dragon who came to power in the marshes now named for him sometime after the 50th Dark Times. He ruled them, and much of the death side until after the 52nd Dark Times, by which time he had been a Great Wyrm for over a millenia, and he entered his twilight and died. Scholarly opinion is that, had he still been alive when the Knights of the Silver Dragons began enslaving the remaining chromatic dragons, Zyrbryxion would have summarily wiped them all out for their sins against chromatic dragonkind.