The Asakku are Kindred whose souls have been corrupted by excessive use of Vicissitude. The changes inflicted on the Asakku force them onto a new path, the Path of Asakku, which grants its followers Transmutations – powers that make it easier for the Asakku to learn Vicissitude, convert other Kindred into Asakku, and other abilities.
The corruption of the Asakku manifests itself as an obsession with Vicissitude, both practicing its powers and either corrupting or destroying non-Asakku individuals. The Shadow Crusade of the Tal'mahe'ra has dedicated itself to destroying their infestation and has compiled various myths to explain their existence.
Vicissitude is the focus of the Corrupted's obsessions. It spreads this power through blood and instruction as widely as possible. They resent untainted Kindred who inherit Vicissitude through a Clan or bloodline, devoting special attention to converting or destroying them.
An Asakku can convert other Kindred through several methods, but the infected gain the derangement Sinister Obsession, which manifests as a compulsion to improve their abilities in Vicissitude, and alien voices that strengthen the more dots the vampire has in Vicissitude, voices that erode her ethical resolve, and converting to the Path of Asakku is the only way to "cure" this derangement.