Trazyn the Infinite + Phyrexian Devourer + Walking Ballista

Trazyn the Infinite

Phyrexian Devourer

Walking Ballista

How it works

1. Activate Trazyn using Phyrexian Devourer's ability by exiling the top card of your library, putitng a number of +1/+1 counters on Trazyn equal to the exiled card's mana value.
2. Repeat step 1 as many times as desired, or until your library is empty.
3. Activate Trazyn using Walking Ballista's ability by removing a +1/+1 counter from it, dealing 1 damage to any target.
4. Repeat step 3 as many times as able/desired.