Infinite +1/+1 counters on a creature, Infinite self-discard triggers
Put a +1/+1 counter on Evolution Witness.
Evolution Witness triggers, returning an artifact or creature card from your graveyard to your hand.
Thran Vigil triggers. Holding priority, activate Iron-Shield Elf by discarding an artifact or creature card.
Resolve the Thran Vigil ability, putting a +1/+1 counter on Evolution Witness.
Repeat from step 2.
Component Cards
How It Works
Put a +1/+1 counter on Evolution Witness.
Evolution Witness triggers, returning an artifact or creature card from your graveyard to your hand.
Thran Vigil triggers
Holding priority, activate Iron-Shield Elf by discarding an artifact or creature card.
Resolve the Thran Vigil ability, putting a +1/+1 counter on Evolution Witness.
Repeat from step 2.