Bone Shredder

Strip away the keyword and what you have is Nekrataal stapled to a flier: a 1/1 for that destroys target nonartifact, nonblack creature the instant it lands. The body is irrelevant. You are buying the kill, and the price tag is honest because echo bills you again to keep the creature past your next upkeep. The default arc is simple: it lands, it kills, and unless you pay a second time, it dies on schedule. That tax is the balancing weight on a removal rate that would otherwise be undercosted, and the design assumes most pilots will let the 1/1 expire rather than re-buy it. The sleight is that the destroy clause keys to the creature entering, not to surviving. The echo cost is optional, and the correct shell never pays it. Bounce it, blink it, or sacrifice it before upkeep and it re-enters, re-triggering the kill, while the new object's echo can simply be declined to let it die again. Echo on its own is a mana tax that forces a sacrifice; wrapped in flicker or recursion, that downside inverts into a loop that re-runs targeted removal every cycle and declines the tax entirely. That is the structural lesson worth keeping: a genuine cost printed on the card that the right pilot simply refuses to pay, and the kill keeps coming.