Enter the Abyss
With this manifestation of Obtenebration, the user can physically enter the Abyss and stay there for as long as she wants. She can also exit from any shadow anywhere in the world, as long as she has seen her intended egress location. With additional effort, she may also bring another person along (willing or no) and possibly strand him in the Abyss.
System: The player rolls Strength + Occult (difficulty 7) for the character to enter the Abyss. The character may take a willing person along; this requires the player to spend a point of Willpower. If the vampire wants to take an unwilling victim with her, she must first establish a solid grasp on him (possibly requiring a roll to grapple). The player spends a point of Willpower and then enters into an opposed Willpower roll against the target (both rolls are difficulty 6).
The character may exit the Abyss at any time. Anyone taken along must be touching the character in order to exit. Stranding someone in the Abyss is said to be a favorite punishment of a certain Lasombra Methuselah. The user can exit anywhere she has previously seen (including places viewed only through Auspex), as long as a large enough shadow is present.
What exactly the Abyss is, how it is perceived and what lurks there is best left up to the Storyteller. It is a highly disturbing place, and anyone entering it for the first time should roll Courage + Obtenebration (difficulty 9). On a failure, a temporary derangement is inflicted. On a botch, the derangement is permanent. Staying in the Abyss for too long is not a good idea. Demonic creatures lurk in the Abyss and might decide to attack the character. In addition, the Abyss itself has an insidious influence upon those who stay there, and anyone spending too long in it might find himself becoming more and more obsessed with suffering and darkness.