Yeah it won't list anyone as their Master that way, but like they mentioned you can change them back human, take the to see Vlad and do introduction. If you dont have enough friendship to ask him ( or you can use MCCC under control and make Vlad turn them) or you can have your Sim play pipe organ and ask him to mentor, its a fast way to gain friend points with him and then ask.
But if you want to use the cheat to make Vlad turn your Sim, you dont even have to do an introduction. Go to him or use cheats on mailbox to bring him to you and invite him in, then clicking on Vlad, go to MCCC cheats, MC Control, then click your Sims portrait, then choose Vampire option, then Turn into Vampire and it will make Vlad turn your Sim.
