Walking Ballista + Unspeakable Symbol + Gratuitous Violence + Quest for Pure Flame

Walking Ballista

Unspeakable Symbol

Gratuitous Violence

Quest for Pure Flame

How it works

1. Activate Quest for Pure Flame by removing four quest counters from it and sacrificing it, doubling all damage dealt by sources you control this turn.
2. Give Walking Ballista lifelink, if needed.
3. If Walking Ballista has less than two +1/+1 counters on it, activate Unspeakable Symbol by paying 3 life, putting a +1/+1 counter on Walking Ballista.
4. Activate Walking Ballista's second ability by removing a +1/+1 counter from it, dealing 4 damage to an opponent or a permanent an opponent controls, and causing you to gain 4 life.
5. Repeat from step 3.

This loop turns your life total into a lethal engine, using Unspeakable Symbol to constantly refill Walking Ballista with counters by paying life at the cost of three life per activation. Each counter removed from Walking Ballista lets it ping an opponent for 1 damage, but with both Gratuitous Violence and a sacrificed Quest for Pure Flame amplifying that output, every single ping is doubled twice to deal a massive four damage instead. If you manage to give Walking Ballista lifelink along the way, that quadrupled damage gains you back more life than you spent to fuel the Symbol, letting you repeat the process until your opponents are reduced to zero.