Fangs of the Vampire

2nd-level transmutation
Casting Time: 1 action
Range: Self
Components: V, S, M (a drop of vampire vitae)
Duration: Concentration, up to 1 minute
Book of Vile Darkness

For the duration, you grow long fangs and can bite a creature within 5ft of you that you can see. When you cast this spell, and as an action on subsequent turns, make a melee spell attack against the target. On a hit, you deal 2d10 necrotic damage to the target.
 
At Higher Levels: When you cast this spell using a spell slot of 3rd level or higher, the damage increases by 1d10 for each slot level above 2nd.**

Fangs of the Vampire King: 2nd level Corrupt transmutation spell. Casting time 1 action. Personal range. Components S. Duration 10 minutes. The caster grows vampirelike fangs that allow them to make bite attacks using a melee spell attack with a +2 bonus. The caster's bite attack deals 2d6 points of necrotic damage and reduces the creature’s maximum hit points by the same amount.

Corruption Cost: 1d6 STR damage

Any spellcaster that prepares spells can learn these spells. Each spell list has an alignment attached to it. If a creature of a different alignment casts one of these powerful spells, their alignment shifts towards the alignment of the spell by one step. Each spell has a corruption cost that is paid when the duration of the spell ends or according to the spell’s description. If the cost is ability damage, it is restored when the caster finishes a long rest. If the cost is ability drain, it does not recover until the creature receives attention from a Greater Restoration spell.