Hikari, Twilight Guardian

The recursion here keys off the stack, not the graveyard or the battlefield: every Spirit or Arcane spell you cast offers a chance to exile this 4/4 flyer and return it once the turn winds down. The text is strict in a way that matters. It exiles only itself, never the board around it, so the effect is a personal reset rather than a hatch for milking other creatures' enter triggers. The ability does little in isolation beyond shielding an evasive body. What gives it teeth is the delay on the return. Because it comes back at the next end step rather than immediately, blinking it during an opponent's turn pulls it clear of their removal window (a sweeper, a targeted kill, an unfavorable block) and restores it untouched once the threat resolves. The card belongs to the Spirit-Arcane overlap that defined its archetype, where Spirit bodies and Arcane instants were two faces of one design: lean into both halves and the dodge becomes repeatable, since nearly every spell you were already casting doubles as a chance to phase a sizable threat out of harm and back. This is chassis design from an era when those two card types were deliberately wound together, asking for full commitment to the overlap. Lean into either half and you get a self-protecting clock that costs nothing extra in sequencing.