From my knowledge of both morrowind (test) and oblivion we have blood magic. So here is my way to introduce the class. To unlock it though one has to have finished Manimarco and have a character of CP100. So basically you are an x- worm cult acolyte that looses his memory when the plane meld is stopped. You wake up in cold harbour. The story starts with you running into myredia that helps redeem you. You as such choose to join Tamreal and to make the world a better place.
Class exclusive to Daedra, dark elves. This daedra are smaller and look almost human. Not red with horns.
Skill line:
Mask of bones: allows the cultist to raise an Daedra but costs 1% of max health every 4 seconds it's summoned. Morph 1: The deadra leaches Magicka instead of health. Morph 2: the deadra heals you 10% of the damage it does
dark tendrils: opens a rift in the ground from which claws shred anything inside. Morph 1: deals more damage the longer in area. Morph2: grants major sorcery to all allies inside
Soul feast: bleeds the enemy and drinks his soul (like vampire spell). Morph 1: Becomes AOE spell but reduces dps in half. Morph 2: range is increased by 100%
Aspect of Daedra: for 10 seconds raises 15 daedra to attack but costs 75% of your health. Morph 1: enemy movement is slowed by 50%. Morph 2: adds another 15 Daedra but reduces time to 5 seconds,
Vanish: blend with the shadows making invisible but next hit in you is 100% to critical. Morph 1: creates a fake copy that explodes if its hit. Morph 2: vanish giants major sorcery for 8 seconds.
Epic skill: transform into a daedra lord: giving all your skills 100% critical and 100% leach for 10 seconds. Skill duration increased x2 for each transformed player.
Traits:
Anguish: -1,4,7% magicka cost to spells
Fiend fire: attacks do 1,9,25% more damage but cost same amount of max health for each attack done
Summoner: increases the power of daedra spells by 5%
Revenge: upon death and reviving all stats increased by 1000% for 1 min