Haha. We get the ability to turn in Cthulus as a gift from Hermaeus Mora.
Oh, how awesome. I suppose we should have tentacle Molag Bal action-style finisher moves, too?

This DLC looks great.
Hircines motives are clear paste "OMG, I WANT TO HAVE FUN AND KILL THINGS", While Mora is so alien and un-human that he appears as a lovecraftian mass of tentacles or a "WRETCHED ABYSS"
From your point of view. But there is no thrill to read books in his realm. No true beauty. No crimson art! Something like the Shivering Isles would be good.
Hell, I would be glad to see Sanguine's Realm, which should bump up that Rated M mark a bit higher.
http://www.castlexplorer.co.uk/england/rising/rising_photos.php#main.
In this case, knowledge can kiss Hircine's ass.