Labyrinth Guardian

The sacrifice trigger is a strict liability dressed up as a body, and reading it as protection gets the math backward: when an opponent points removal at it, the creature dies before the spell resolves, so they still get their one-for-one. The clause doesn't punish removal; it broadens it. Any targeted spell becomes a kill spell here, which means bounce, a single point of burn, even a tap effect all function as hard answers to a 2/3 they would otherwise have to fight through. It also fences in your own deck: a pump spell or a protective aura sacrifices it just as fast as an opponent's burn, so the creature wants to sit untouched and trade in combat. The Illusion lineage is the heritage talking, the Phantasmal family of cheap fragile bodies that fold to a single answer, though this one narrows the trigger to spells only rather than spells and abilities, so activated and triggered abilities leave it standing.

Embalm is what makes the fragility survivable. The downside is that an opponent's removal is always live; the back half is that it costs them a card to cash in a creature you can raise again from the graveyard, exiling this card as part of the cost to make the token at sorcery speed, spending mana you'd often have spare. The wrinkle worth sitting with is that the embalmed token is a copy, sacrifice clause and all, so recursion doesn't buy you a sturdier creature. It buys you the same fragile wall a second time.