From Path of the Vampire Wiki
Death Definition: Dying as vampire simply refers to being sent to the Shadow Realm. In order to be sent to the shadow realm, you must be drained of all blood followed by a critical wound. You may also choose to 'kill' your character on the settings page.
Inside Shadow Realm: While you are in the Shadow Realm you will find spirits and other vampires to drain anima from. To leave the Shadow Realm you must wait a certain amount of days. Once you have spent the required amount of days, you must then find an exit to return to the living world. WARNING: Exits move randomly.
Getting Anima:To build up your anima before you leave the shadow realm, and lower your death woulds you have a couple of options. the first is to find spirits, bite them and receive one anima. The second is to push the $ button (same as robbing a character) and you will rob them of 1 anima. The third is to push the Attack button on a character. By doing this, you not only rob them of 1 anima but will increase one of their death ones by 3 days. If you choose the third option, remember that this can be done to you and that the character might hold a grudge past death.
Helpful Powers: There are powers that can assist. Immortals can use life link which allows them to leave after gaining their anima without the need of an actual exit. Fadewalkers can also enter the Shadow Realm at will, so long as they have not been sent there through death. However to get out of the Shadow Realm they must use a doorway as the power is a one a way ticket. This allows them to share their anima with allies and lower their death would as need be. Fadewalkers can also use shadow crafting block squares, protecting themselves and others inside the square until the day change. After that the blocked square dissappears. This power also allows them to edit the shadow realm at will.
Return: Upon returning from the Shadow Realm you will acquire a 'Death wound' that has a random stat loss of 2 points (3 for necromancers). Death wounds last for 3 months time and appears on your wounds page. If you kill yourself, the death wound will have additional penalties in stat loss. To lessen the number of days on your death wound, you might want to consider staying inside of the Shadow realm longer to bite spirits and steal anima from other characters. Each anima you take in will reduce one death wound by one day.
Death as a human is currently permanent. When you have been drained of all your blood, the last vampire to feed from you is given an option to 'kill' or 'turn' you. If you are killed you will be sent to the Shadow Realm. As a human there is no way to leave. However, in the future there are plans to allow humans the option of becoming zombies and/or ghosts, so all may not be lost for your human character if you have been killed.
If a vampire decides to turn you, they will become your sire. There is no way to reverse this unless you choose to delete your character completely. Your stats will raise to the starting stats of the path you chose at character creation plus any additional stats you earned as a human.