Having one charge being wasted on a pet is silly.
I also think that is has way too long of a duration to be fun. It lasts 60 seconds with a 30 second cooldown which makes it more of a passive ability rather than an active ability.
Lastly, its only good against melee....can't even be used as dispel fodder against caster...
Here's my suggestion so bear with me. I think it needs to become a more active ability, I have read blue post with my own eyes that say they like these type of abilities in pvp.
What do i mean by this?
I mean it needs to only last like 5 seconds
On top of this "nerf" It needs a huge buff to fix the clunkieness of the spell.
Firstly, it needs to fear ranged as well, Blood Fear was OP because it allowed for CC on healers that peak their heads out from LoS, as long as they don't attack the warlock it won't happen.
The last change that might sound scary/OP is that it needs to Horrify all attackers that attack in the brief duration of the spell and not be consumed/removed by attackers. The duration and cooldown could be adjusted to whatever is balanced.
Here would be a polished Description.
Blood Horror--Lasts 5 Seconds--Cooldown 50 seconds(up from 30 seconds)--Consumes 5% of Max HP
While active, all attacks done to the warlocks will inflict horror on the respective attackers for 4 seconds. Each attacker can only be effected once per cast of blood fear. (This means if they trinket the spell they won't be horrified again if they go in for another attack)
This isn't some plot of mine to make warlocks OP, its a suggestion that fixes the whole 1 charge thing, and it also makes it not useless against casters while not revisiting the old blood fear.