Crystalline Crawler + Light of Promise + Emiel the Blessed + Gray Merchant of Asphodel
Crystalline Crawler
Light of Promise
Emiel the Blessed
Gray Merchant of Asphodel
Infinite +1/+1 counters on a creatureInfinite blinkingInfinite colored manaInfinite creature ETBInfinite lifegainInfinite lifegain triggersInfinite lifelossInfinite creature LTB
How it works
Activate Emiel by paying 3, blinking Gray Merchant.
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.
Crystalline Crawler triggers, putting at least four +1/+1 counters on itself.
Activate Crystalline Crawler's first ability three times by removing three +1/+1 counters from it, adding 3.