Kentaro, the Smiling Cat + Kor Skyfisher + Urza's Incubator + Rukarumel, Biologist

Kentaro, the Smiling Cat

Kor Skyfisher

Urza's Incubator

Rukarumel, Biologist

How it works

1. Cast Kor Skyfisher by paying 0.
2. When Kor Skyfisher enters the battlefield, it triggers, returning itself from the battlefield to your hand.
3. Repeat.

This engine relies on Rukarumel, Biologist to blanket your entire deck and battlefield—including Kor Skyfisher—in the chosen creature type, which Urza's Incubator then discounts by {2}. Kentaro, the Smiling Cat lets you pay {0} instead of any Samurai spell's mana value, completely bypassing Kor Skyfisher's standard cost when combined with the Incubator's reduction. Because Kor Skyfisher's enters-the-battlefield trigger forces you to bounce a permanent, you simply bounce the Skyfisher itself right back to your hand, allowing you to replay it endlessly for free. This continuous loop generates infinite entry and leave-the-battlefield triggers alongside an arbitrarily high storm count.