Saziel

I've never found an upstairs. I've never seen a staircase. Argh.. I guess I'll look again, but I have no idea how I would've missed it..

I have the quest for this, but I'm not finding him anywhere in the Slith Castle. I've killed seemingly everything, but I've never found him. I figured maybe I killed him without realizing it, but the quest wasn't able to be turned in. I feel as if I'm missing something very obvious, but I've scoured through the Slith Castle a good 4-5 times. Any hep would be appreciated.