Torpor is a term used to describe the state of deep slumber that vampires enter into for prolonged periods of time for hibernation or after suffering catasphrophic damage.
Rather than dying at -100 health, vampires will now enter a state of fake death called Torpor.
Vampires in Torpor can only be killed by decapitation, getting their heart cut out, or being dealt 100 extra damage past the normal death threshold.
You cannot wake up from Torpor whenever you want, instead you have to wait a certain length of time before you can spend a blood point to heal back to just above crit and re-awaken.
If you have no blood, you cannot re-awaken. Feeding a vampire who's ready to re-awaken your blood will immediately wake them back up.
Succumbing now actually works, but torpors you if you're in crit. If you succumb while in torpor, you just die.
You will automatically slip into Torpor as a vampire after 2 minutes of being critted, like how humans die if they stay critted for too long.
Unless you mangle their corpse, you will no longer know if the people you kill are actually vampires. They seem completely dead if Torpored.