I'm gonna buck the trend and call this guy a priest of Hermaeus Mora. The DLC files mentioned his plane of Oblivion, right? And tentacles. Well, Hermaeus Mora is commonly depicted as a gigantic squid with too many eyes, so tentacles make sense, even as an attack one of his priests would use.
Also, I have this to say about Solstheim (and everything else):
YES.
HELL YES.
HELL.
F***ING.
YES.
Also, I have this to say about Solstheim (and everything else):
YES.
HELL YES.
HELL.
F***ING.
YES.