Omen Bairn

Whenever an opponent attacks you, they
lose 1 life and you gain 1 life.
{2}{w}{b}, {t}, sacrifice Omen Bairn: target creature gets -X/-X until end of turn, where
X is the amount of creatures you control.
'Omen babies have all their horns excised, causing most to perish. These fetishes are made
to memorialize them.'