At the beginning of your end step, exile up to one target artifact you control and up to one target creature you control. Then return them to the battlefield under their owners' control.
Don & Leo turns your end step into a free blink engine, exiling and returning one artifact and one creature every turn to retrigger enter-the-battlefield effects, reset counters, and dodge removal. Deploy value ETB creatures and artifacts early, protect Don & Leo so the loop never stops, and snowball card advantage and board presence until you bury opponents in incremental value or assemble a blink-powered combo.
Free, repeatable blink of both a creature AND an artifact every turn without paying mana
Strong ETB value engine in the best two-color pair for blink (UW)
Vigilance lets the turtles attack and still hold back as a blocker
Can reset planeswalker-style artifacts, untap mana rocks, and dodge targeted removal at instant speed-ish timing
Flexible: targets are optional, so it never forces a bad blink
Blink only triggers on your end step, so it's slow against fast combo and aggro
Heavy reliance on the commander makes it vulnerable to repeated removal and stax
Color identity lacks ramp and big mana, so casting a 5-drop commander multiple times stings
ETB payoffs are dead cards without the engine online
Blinking tokens and Auras/counters can backfire or lose value
Saves your board and commander engine from wraths and combo turns.
Add cheap, flicker-friendly card-advantage ETBs (Spark Double, Eternal Witness via blink loops) and instant-speed protection like Heroic Intervention's UW analogs to keep the engine alive. Tighten the mana base with fast rocks (Arcane Signet, Talisman of Progress) and fetch-fixing, and add a tutorable combo line such as Felidar Guardian + a blink permanent or an infinite-ETB payoff. Cut high-cost vanilla creatures for low-mana value engines so every blink does meaningful work.
Legendary Creature — Mutant Ninja Turtle
