Chainer, Dementia Master + K'rrik, Son of Yawgmoth + Gray Merchant of Asphodel + Dimir House Guard
Chainer, Dementia Master
K'rrik, Son of Yawgmoth
Gray Merchant of Asphodel
Dimir House Guard
Infinite death triggersInfinite creature ETBInfinite lifegainInfinite lifegain triggersInfinite lifelossInfinite creature LTBInfinite creature sacrifice triggersReturn all creature cards from all graveyards to the battlefield under your control
How it works
Activate Dimir House Guard by sacrificing Gray Merchant, regenerating it the next time it would die this turn.
Activate Chainer by paying nine life, returning Gray Merchant from your graveyard to the battlefield as a Nightmare in addition to its other creature types.
Gray Merchant enters the battlefield, causing each opponent to lose life equal to your devotion to black and causing you to gain life equal to the amount of life lost this way.