This power is useful if the player accidentally causes a character to attack (whether through a quest, by assaulting them, or by using Frenzy), or if the player wishes to talk to an adversary (accidental or not) who will not yield.
If the player needs time to self-heal or recover from fatigue. It may hold a creature or person fairly still allowing time to recover.
If the player is taking on two enemies at once Vampire's Seduction may be used on one of them while attacking the other; however, attacking the target will raise its aggression level, so further seducing will be required.
Also useful when the player's vampirism causes nearby characters to be hostile.