How it works
Prerequisites
- You control at least one additional creature with a +1/+1 counter on it.
Steps
- 1Activate Phyrexian Altar by sacrificing another creature with a +1/+1 counter on it, adding one mana of any color.
- 2The creature dies, triggering Basri's Lieutenant's second ability, creating a 2/2 Knight creature token.
- 3When the Knight enters the battlefield, Serra Redeemer triggers, putting two +1/+1 counters on the Knight.
- 4Repeat.
Commander brackets
In which brackets is this combo allowed, per Spellbook's Exhibition tier?