Ruebenbrei

My guess would be Nyx. With a primordial like Ouranos being afraid of her, it should be a female primordial at least. In greek mythology, Nyx also had a reputation that other gods were afraid of her. There are also a few other options from non-greek pantheons though.

1

[Blood Armament]: Create a defensive blood armor. [Blood Pool]: Creates an orb of blood that stores the blood of victims and drains their MP. The user can then use the stolen MP for himself. [Mist Form]: Temporary changes the user's body into mist, nullifying all physical enemy attacks. [Summon Household]: A skill that allows the user to summon different familiars, such as bats. [Blood Frenzy]: The more blood the user’s body is covered in, the stronger his attack power becomes. As a consequence, the user will slowly lose control of his mind and becomes unable to hold back his urge to slaughter (side effects won’t be applied with his status as a legend).

Had to look this one up, it's from Jeffrey Gaines.

Yellowcard

I see a pattern with these titles :D

If she suddenly became a Gryffindor or Hufflepuff, sure.

I am getting Persona 5 vibes right here