Cheat the Scale of Anubis
Egyptian legend has it that the god Anubis weighs the hearts of the deceased on his great scale. If the heart is not in perfect balance with the feather placed on the other plate, it is considered to be weighed down by sin, and the soul of the deceased is fed to the Devourer and destroyed. Setite faith sees this story as a corruption of the dark truth: Anubis acts as a gatekeeper for the tyrannical Osiris, who rules the afterlife. Those who have proven their soul's strength by being willing to reject the laws that make them slaves (hence those who have "sinned") are destroyed before they can enter the afterlife and overthrow the tyrant-god. If Set and his followers are ever to reverse this state of affairs, there must be a way for the strong to get around Anubis's scales. This power allows a master of Serpentis to do just that by removing his heart (as well as his other vital organs) from his body entirely and wrapping his flesh in a protective cocoon.
The power, more akin to a ritual, can only be performed in the dark of the night - either after the moon has set, before it has risen or during the new moon - and only on oneself. It takes a few hours to complete. Once the Setite has removed his heart and other vital organs, he must place them in specially prepared clay urns (called Canopic jars). After that, servants can bury or hide them away. After the vampire has removed all his major organs, his vitae and undead flesh combine to wrap him in a dry, scaly shroud that is nearly impenetrable. Only a small opening over his mouth remains in the shroud. The character than falls into a sort of torpor. Only feeding him his removed internal organs can awaken the character. Once that is complete, it takes about one minute for the cocoon around the Setite to crumble to dust.
The enshrouded vampire is virtually impossible to harm - no known direct force, from inferno to high-noon sunlight, can do him damage while so wrapped. However, the extracted organs are vulnerable, most especially the heart. Exposing it to fire or sunlight causes the vampire's instant and terrible immolation, destroying him. Although terrible, this destruction is actually the final part of the ritual - in which the vampire's followers burn his organs before a statue of Set. By meeting the Final Death in this way, a Follower of Set reaches Anubis without a heart and is hence able to pass him by without ever undertaking the test of the scales, entering the afterlife as a powerful agent of his god.
It is possible to undertake this ritual only part way, something usually done for one of two reasons. The first is to assume the fully enshrouded form for protection's sake, which some Setites do when they are traveling. Their ghouls carry them as cargo in a ship or caravan and then feed their master his organs when they arrive at their destination. The other option is to stop the ritual with the removal of the heart. The vampire is perfectly able to move about without his heart, but he becomes immune to standard staking or diablerie. However, if an enemy gets hold of the Canopic jar containing the extracted organ, the vampire is in serious trouble. Not only does it provide a powerful ritual connection to the vampire, but a simple flame or glint of sunlight can destroy the vampire outright, and driving a stake through the organ drives the Setite into torpor.
System: To undertake this ritual power, the vampire must have time to herself (assisted by acolytes, perhaps) and be acting on a moonless night. The power fails at any other time. The player makes an extended Dexterity + Medicine roll (difficulty 7) for the character to undertake the ritual. Each roll means an hour of activity, and the ritual ends in failure if the moon or sun rises before the player achieves the necessary successes (five to remove a heart, 12 to achieve the mummified form). A failure on a roll has no effect other than to extend the process another hour. A botch entails a catastrophic failure that ends the ritual and causes two levels of aggravated damage to the vampire. Any vampire who witnesses the process is subject to Rotschreck (difficulty 6).
The enshrouded body of such a Setite is completely immune to harm. No source of injury - save perhaps the might of a Methuselah or Antediluvian - can do it direct physical damage. The organs, however are extremely vulnerable, and even the slightest sunlight or flame destroys them outright. The jars are opaque, but easily broken open. Except for the heart, destroying an organ causes an unsoakable level of aggravated damage to the vampire. Destroying the heart destroys the vampire outright.
The removed organs are rich with vitae. Most contain one blood point's worth (which reduces the vampire's overall blood pool), and that blood remains fresh indefinitely in the withered organ-meat. A ghoul or vampire who consumes a Setite's removed organ takes one step toward the blood oath as normal. The heart contains two blood points and a vampire consuming it is attempting diablerie against the Setite. Once the two blood points are drained from the heart, the attacker passes straight to the heart's blood and her player must make a Strength roll as normal, save that the difficulty is 7. Staking the heart stakes the Setite if he is still active.
Note: This last sentence contradicts the last sentence of the introduction. Since it is in the "System" section, it takes precedence: Staking the heart stakes the heart's owner. I suggest that doing bashing damage causes unsoakable damage to the Setite, potentially causing him to enter torpor. Doing Lethal or Aggravated damage to the heart kills the Setite. -Jamie