Infinite black mana, Infinite death triggers, Infinite ETB, Infinite LTB, Infinite sacrifice triggers
Activate Mairsil using Endling's third ability by paying , giving Mairsil undying until end of turn.
Activate Mairsil using Blood Vassal's ability by sacrificing it, adding .
Mairsil dies, triggering its undying ability, returning it from your graveyard to the battlefield with a +1/+1 counter on it.
Activate Mairsil using Barrenton Medic's second ability by putting a -1/-1 counter on it, untapping it.
Repeat.
Component Cards
How It Works
Activate Mairsil using Endling's third ability by paying , giving Mairsil undying until end of turn.
Activate Mairsil using Blood Vassal's ability by sacrificing it, adding .
Mairsil dies, triggering its undying ability, returning it from your graveyard to the battlefield with a +1/+1 counter on it.
Activate Mairsil using Barrenton Medic's second ability by putting a -1/-1 counter on it, untapping it.
Repeat.