Venser, Shaper Savant + Displacer Kitten + Pact of Negation

Venser, Shaper Savant

Displacer Kitten

Pact of Negation

How it works

1. Cast any other spell by paying its mana cost, or wait for an opponent to cast one.
2. If the spell is a noncreature spell that you cast, Displacer Kitten triggers.
3. Holding priority, cast Pact of Negation by paying 0.
4. Displacer Kitten triggers, blinking Venser.
5. Venser enters the battlefield, returning Pact of Negation to your hand.
6. Repeat from step 3.