Satoru Umezawa

Ninjutsu was born as a combat trick tied to unblocked attackers: swap a small evasive creature for a bigger one at the exact instant damage would be assigned, dodging summoning sickness and untapping nothing. For most of its life it stayed a niche mechanic gated by the size of your ninja pool. This blows that gate open by granting ninjutsu to every creature card in your hand, so the swapped-in threat is no longer a modest ninja but whatever bomb you happen to be holding. Sneak an eight-drop onto the battlefield at instant speed off an unblocked attacker, and the summoning-sickness and mana-cost questions both evaporate at once. The dig trigger is the second half of the engine: each ninjutsu activation looks three deep for the next creature to cheat in, refilling the hand you keep emptying. That dig fires only on the first ninjutsu of a turn, which is what stops the loop from spiraling, since the ninjutsu cost itself is fixed and repeatable across as many attackers as you can send in. What makes the design coherent is the body: a 2/4 is an awkward attacker, which is the point. It wants to hang back, bounce its own evasive creatures, and use them as delivery vehicles rather than swing itself. A decade-old fringe mechanic, reframed as a wholesale cheat-into-play plan.