Prof. Rudolph van Richten

Whenever Prof. Rudolph van Richten and/or
one or more other Vampires enter the battlefield under your control, create a Blood token. This ability triggers only once each
turn. (It's an artifact with "{1}, {t}, Discard a card, Sacrifice this artifact: Draw a card.")
{2}, Sacrifice another creature or a Blood token: Each opponent loses 2 life and you gain 2 life.