Nothing special just adds a more powerful vampiric drain for non vampires. Tome can be found in riverwood trader. this is my first mod if you wanna call it that. This is part of a vampire themed mod i may do if i get permission from the authors to use their items. 
Vanilla:
Damage: Drains 5 health per second

Vampiric Drain Plus:
Damage: Drains 20 health per second (also does damage over time for 5 seconds)