Sparkcaster

A 5/3 for four with a built-in rebuy: that combination is the whole pitch. The mandatory bounce, which looks like a tax, is what turns this Kavu into an engine, because the only creature it ever needs to return is itself. Re-cast it, get the ping again, repeat. The deck this was built for ran enter-the-battlefield payoffs in two colors and wanted a body that could loop them on a clock; Sparkcaster carries both halves of that loop in one card, the recursion enabler and the burn it pays out. The damage is restricted to a player or planeswalker, which fixes its job as reach and inevitability rather than removal: it grinds a life total or chips a walker down, never trades in combat. That restriction matters, because the recurring damage is the part that would be oppressive if it could also clear blockers. The tension that defines the card is the loop's tempo cost. Bouncing a fresh value creature each turn is the dream, but with nothing better on the board you bounce the Kavu, resetting the trigger while handing back four mana of progress: a fair price for a self-fueling damage source. It is a build-around wearing a beater's body, the kind of incremental-value engine the era it comes from was full of, with the added threat of swinging for five whenever the ground clears.