While the following isn't an actual bug, I do believe that it needs to be looked at, and I'm not sure where this should be posted honestly (so forgive me for posting this here if this is the wrong place for it)...
The Vampire Lord gear set (for the 5th piece bonus) buffs all Vampire abilities for up to 400 points of Spell Damage; with the exception of Baleful Mist (which almost nobody uses) all Vampiric abilities do Magicka based damage...
In this regard, War Maiden is significantly superior as its 5th piece bonus buffs all Magicka based abilities for up to 400 Spell Damage..
Now, Vampire Lord does throw in a 5% reduction for the Magicka Cost of Vampiric abilities with the 5th piece bonus, but (IMHO) that does not equal the benefit of a set that buffs all Magicka based abilities by 400 points...
Could we (for example) have the 5th piece bonus for Vampire Lord either bestow more Spell Damage for Vampiric abilities or offer something better than a 5% reduction in Magicka cost for Vampiric abilities?
Maybe the 5th piece bonus could add a 1-2 second buff to the duration of Vampiric abilities instead...
Anyway, this is something I thought needed attention, and thanks for reading this...
Unyeilding Bias
PSN TheLordofMurder
PS4 NA
Magicka Templar
DC
The Combat Physician:
https://www.youtube.com/watch?v=ZKaqUVm_8JE&t=142s