Grystok
Friar Grystok was a vampire who served the Three Mad Sisters. Aside from the sisters, he was seemingly the leader of a group of vampires on a coffin ship in the Dark Times that he was using for enforced labour.
After Rose Tyler was kidnapped by his pet vampire bat Hugo, Grystok greeted her with suspicion and prepared to present her to the Three Mad Sisters. Later, the Ninth Doctor and Medicus Androkan caught up to them. Grystok viewed Androkan as worthless and killed him. As he led the Doctor to the sisters, he discovered them to be "barely unalive", having been attacked by Rose, who was now converted to a vampire herself. Grystok ordered his chief guard, Drogann, to kill her, but was interrupted by an attack from Rassilon resulted in Hugo being killed by Drusa.
As Drogann captured the escaping Doctor and Rose, Grystok reappeared to urge him to kill them, leading Drogann to throw his dagger at Grystok and send him falling to his death - something he claimed to have wanted to do for "over 300 years". (COMIC: Monstrous Beauty [+]Loading...["Monstrous Beauty (comic story)"])
By February 2024, UNIT's visual interface's stash of cards related to the Kotturuh crisis included a depiction of Grystok, alongside records of the Great Vampires, the Tenth Doctor's Time Lord Victorious persona, and the vampirised Rose Tyler. Data recovered by Sasha from the coffin ship to which the Entity had transported her allowed UNIT to upgrade all these cards to Level III status. (WC: Incoming Transmission - February Update Video [+]Loading...["Incoming Transmission - February Update Video (webcast)"])
