Displacer Kitten + Guile + Mystic Snake

Displacer Kitten

Guile

Mystic Snake

How it works

1. Cast any noncreature spell from your hand by paying its mana cost, or wait for an opponent to cast one.
2. Holding priority, cast Mystic Snake by paying 1.
3. Mystic Snake enters the battlefield, exiling the spell and causing you to cast the spell from exile without paying its mana cost due to Guile.
4. Displacer Kitten triggers, blinking Mystic Snake.
5. Repeat from step 3.