So both these ults are kinda bland that they still use your weapon and skills so lets spice it up.
Necromancer bone goliath morph or hase ability
You use your fists made of bone for your basic attacks. Your light attacks deal x amount of damage and cause (insert affect, mabye disease damage to fit the theme?) Your heavy attacks cause a circle AOE in front of you, causing enemies to be taunted but also enraged, dealing %x more damage to you. (This is so there is a downside to this powerful taunt and it isnt a insanely good abilitu)
Vampire ult ability base or morph-your basic attacks are now changed to (insert ranged magical damage? Werewolves go for stamina so vampire ult could fit as a ult for magicka users? Just a idea)
Whenever you attack a enemy with a heavy attack that is under %5 you have a x% of Health and is not a boss or rare monster (idk what to call mobs with unique health bars) it has a chance of turning them into a bloodfiend with half the health the mob has dealing bleed damage on its attacks (will only do basic attacks to make it not OP and busted) this effect can occur every x seconds.
I know it might sound broken but thats why I put x as a replacement for numbers so it can get tuned. I think the general concpet of a bone collasus smashing the ground isnt far fetced as we've seen enemy bone collasuses do this. The vampire effect seems OP but really it's actually what makes vampire balanced. Creating heavy downsides and not many great abilities and putting all the power to balance it out into it's ult.
Tell me what u guys think. I got the idea for vampires doing magical attacks because I believe thats what happened if you became a vampire lord in skyrim.