Cephalopod creature in Tamriel Data is infamously frustrating to fight due to some misalignment in its hit box - you need to aim at some spot above the creature to land a hit.
This is a claim to fix that. Generic cephalopods in Data:
In the base game, you can get Fast Eddie to steal the Amulet of Unity as a chore. He will tell you that he had to steal it from a heavily guarded location on the mainland. The player after quest completion and having the amulet in their inventory can choose to return it to Master Vaerin in Alt Bosara. The reward for doing so will be something pitiful as is typical of a telvanni master (and also your mouth stole from him). A steel dagger with 20 health with a 0-5 flame on strike enchantment called Sunshard (the name really oversells the crappy dagger in reality).
TR_SS02_Naram Abandoned Velothi tower. Tower being looted by a trio of hostile outlander adventurers who have recently arrived at Marog. The dome section is occupied by a reclusive minor rogue Telvanni.
A unique spell for the Daedric Septis book (become a giant dremora fire damage + poison both on touch and on self), with a script attached to the book which teaches that spell if the player has enough intelligence.
Mistress Faruna in her reclusive research has uncovered notes by one Master Turimal, an old Telvanni wizard who was the prior inhabitant of Tel Oren. Turimal discovered and fished out of Bthalag-Zturamz the legendary staff Oathrung, which granted him enormous power. He let the power get into his head, however, and attacked Firewatch itself in 306, during which he was captured and executed.
Note: This questline is meant only as a temporary stopgap, to close up the current Telvanni cliffhangers. As such, these quests will be DELETED once the real Telvannis redo starts in many years' time. Hence, please make the questline very simple and don't spend too much time on it.