Glass-Cast Heart (Extended) [Innistrad: Crimson Vow Commander]

Whenever one or more Vampires you control attack, create a Blood token.

{B}, {T}, Pay 1 life: Create a 1/1 white and black Vampire creature token with lifelink.

{B}{B}, {T}, Sacrifice Glass-Cast Heart and thirteen Blood tokens: Each opponent loses 13 life and you gain 13 life.