Board Thread:Lore Discussion/@comment-10167444-20130604182628/@comment-5.179.107.25-20150425203237

That's quite believable - supporting that is that Kaathe, when he tells you to go collect the Lord Souls, says "Seek Gravelord Nito, The Witch of Izalith and the traitor Seath the Scaleless". He simply states the names/titles of the other two Lords, but refers to Seath as "the traitor", implying some contempt for him.