Many ogres extracted blood oaths from the oni they summoned. Others simply extracted blood.

Premium Deck Series: Fire and Lightning

Flames of the Blood Hand

Flames of the Blood Hand deals 4 damage to target player. The damage can't be prevented. If that player would gain life this turn, that player gains no life instead.

Flames of the Blood Hand deals 4 damage to target player or planeswalker. The damage can't be prevented. If that player or that planeswalker's controller would gain life this turn, that player gains no life instead.