Teardrop Kami

A one-drop whose only purpose is to be cashed in. The body never blocks, never attacks, never matters: it exists to be sacrificed for a single instant-speed tap-or-untap of one creature, and the design leans entirely on that one flexible activation. Tapping a blocker before combat clears a path; tapping an attacker pre-combat blunts an assault; untapping is the quieter half, freeing a creature you tapped for mana or convoke, or readying a defender that already blocked. Bundling both directions into one activated ability gives a cheap, replaceable answer to a wide band of board states without committing to either mode when you play the card. The Spirit type and the self-sacrifice clause both reward a shell that wants bodies it can spend, but the truth of the card is simpler than any synergy: it is a Falter effect aimed at a single target, stapled to a one-mana creature so small that the cost of holding it is nearly nothing. That cheapness is the whole pitch and also the ceiling. Because activating it eats the creature itself, the effect fires once. It taps or untaps exactly one creature, then it is gone, leaving you a card down and a single point of board presence poorer.