Moroki not only due to him being able to two shot me, but the place itself made for a difficult fight. If it's a fight, the worst so far was inside Azura's Star.
Oddly, I ran into Krosis after I croaked a dragon but he didn't fight. I took a few shots at him but he just slid away.
Krosis was one of the toughest fights I had in this game...first try I only saw the dragon, so in the middle of the fight I got near the coffin and....well, I got killed in no time by a dragonbreath+fireball combo lol
Second try, I killed the dragon alone, went for Krosis but he killed me...
Third try, I finally killed me but it was verrry challenging...