Gatta and Luzzu | Lae'zel, Vlaakith's Champion

Cards

Gatta and Luzzu in hand or in the command zone.
Lae'zel and
Walking Ballista on the battlefield (
Walking Ballista with two or more +1/+1 counters on it).

({2} magic symbol) ({W} magic symbol) plus commander tax if applicable available.

Cast
Gatta and Luzzu either from your hand or from the command zone by paying ({2} magic symbol) ({W} magic symbol) plus commander tax, if applicable.
When
Gatta and Luzzu enters the battlefield, it triggers, targeting
Walking Ballista.
Activate
Walking Ballista by removing a +1/+1 counter from it, targeting itself, but instead putting two +1/+1 counters on it due to
Gatta and Luzzu and
Lae'zel.
Activate
Walking Ballista by removing a +1/+1 counter from it, dealing 1 damage to any target.
Repeat from step 3.

You can forego step 4 to simply put infinite +1/+1 counters on
Walking Ballista if desired.

This combo has been estimated to be Ruthless (Bracket 4+).