Rukaleth

Rukaleth was a red dragon. Originally a servant of the Estorian wizards in the Ziggurat, the wizard Kask used the Tear of Boccob to transform Rukaleth into a dracolich in a show of necromantic power. Though Kas was ultimately killed when he turned against his fellow wizards, Rukaleth remained bound within the Ziggurat, magically compelled to guard the innermost sanctum. Even after the wizards perished and Estorium fell, Rukaleth remained at his post for centuries, unable to break the spells binding him there. When the Challengers of the Unspeakable attempted to get past him, he openly admitted to feeling little joy in fighting them and was relieved when they ultimately destroyed him.

Rukaleth's relief quickly turned to terror, however, his soul was drawn into the sword Nightbringer and consumed.