In Nomine has that already built-in with Demons of Lust. You probably are looking for Impudites to steal all of someone's Essence leaving them tired and luckless the next day (Essence only recovers 1 point a day at noon for humans). However you could have various other bands do similar things: dominator/rix Balseraph beat you within an inch of your life and leave you begging for more; Calabite dealing soul damage during sex (but never past the point to lose a force), Habbalah manipulating your emotions until your a quivering pool of tears, or Shedim just grabbing your body and convincing you it's OK to do all those naughty sexy things you wanted with another demon until you're broken and spent.

Naturally angels, other demons, Soldiers of God/Hell, Undead, Saints, etc. can do similar if equipped with the right artifacts and songs. For example, Ethereal Song of Attraction creates nigh-all-consuming love in another for hours at a time, which should leave most people similarly exhausted.

And then we could talk about IN SJG ethereal spirits who want worshipers, or at the very least a chance to ravage human for essence -- and sex is just a convenient means to an end.

Did you want mechanical details?

Quote from: Planet Algol;588478...and according to the 1e Monster Manual, yes they do.

It's been so long, i'd forgotten all about that.

Quote from: Planet Algol;588477Doesn't the AD&D Night Hag have the ability to ride it's victims in their sleep and wear them down?

Changeling: The Lost features its own variety of Night Hags, in Dancers in the Dusk (pages 31-33). They are basically dream predators which drop out of nightmares into the waking world in order to drain Glamour and Willpower from their paralyzed victims. They don't always show up as hags, as such, either: for example, in the more modern times the same entities have been responsible for at least some of the UFO stories about Greys appearing in people's bedrooms.