User blog comment:Alva the Wayfarer/Manscorpion Tark is Black Iron Tarkus/@comment-26186424-20150324172727/@comment-184.146.107.118-20150326031559

There is another definition to "seethe," that is the one that Tark was using to describe his master. When a person seethes or is seething, they are filled with a vast yet inexpressable anger. Tark is saying his master changes form so that he can continue to hate the world for eternity.