How it works
Prerequisites
- You have enough mana to cast the creature with MV<=2 if it doesn't have in its mana cost, or enough to cast it with X=1 otherwise.
- Creature with MV<=2 that is colorless and enters the battlefield with a +1/+1 counter on it
Steps
- 1Cast the creature with MV<=2 by paying its mana cost if it doesn't have in its mana cost, or by paying enough mana where X=1 otherwise, causing the creature to enter the battlefield with a +1/+1 counter on it.
- 2Activate Ashnod's Altar by sacrificing the creature, adding .
- 3When the creature dies, Reyhan triggers, putting a +1/+1 counter on Evolution Witness.
- 4Evolution Witness triggers, returning the creature from your graveyard to your hand.
- 5Repeat.
- 6If the creature can be cast for or less, this combo nets infinite colorless mana, and you may cast that creature for an arbitrarily large amount of mana if it has in its mana cost.
Commander brackets
In which brackets is this combo allowed, per Spellbook's Exhibition tier?