Chakram Retriever + Will, Scion of Peace + Invulnerability

Chakram Retriever

Will, Scion of Peace

Invulnerability

How it works

1. Activate Will by tapping it, causing white and blue spells you cast this turn to cost at least 4 less.
2. Activate a creature by tapping it, adding .
3. Cast Invulnerability with buyback by paying .
4. Chakram Retriever triggers, untapping the mana-producing creature.
5. Resolve Invulnerability.
6. Repeat from step 2.