Abuelo, Ancestral Echo

The activated ability is a blink stapled to a body, and the way it's built matters more than the flicker itself. Most repeatable flicker effects live on high-cost engines or asymmetric spells; here it's a three-mana flier that can protect and re-trigger enter-the-battlefield value on demand, at instant speed, targeting your own creatures or artifacts. That instant-speed window is the whole strategic axis: with the exile and return both keyed to the stack, you can respond to a removal spell already targeting your creature by exiling it, watch the removal fizzle for lack of a legal target, and get the permanent back at the beginning of the next end step. It doubles as a way to dodge a sweeper, to reset an artifact whose ability you'd like to re-trigger, or to re-fire a valuable enters-the-battlefield trigger at the moment it matters most. The return-at-end-step clause is what pays for the repeatability: because the permanent comes back only at end step, the ability can't loop into infinite enter-the-battlefield value the way a permanent-return effect would, and it can't sneak a summoning-sick creature into an attack. Ward keeps the flier itself irritating to remove, so the engine stays online. It sits in a line of white-blue value pieces built around flicker (Restoration Angel and Charming Prince gave you one shot; Roon of the Hidden Realm offered repeatable flicker with a return-at-end-step catch of its own), but a defended, instant-speed body is the specific wrinkle that separates it from that line.