Zero Two's comment on Chapter: My Three Wives Are Beautiful Vampires - Chapter 212: A Gentle Demon.

I'm guessing Victor's 7 maids will be the Personification of the 7 Deadly Sin, Kaguya is the sin of Pride, Eve is Wrath, Bruna is Lu**, Roberta is Envy, Maria is Gluttony, and the other two that Victor haven't met yet is Greed and Sloth