Durable Coilbug

Five mana to bring itself back is a rate no one pays for raw card advantage, and that is exactly the design: the cost is set high so the recursion grinds rather than spirals. The 2/2 body is beside the point; the self-returning ability is the whole reason it exists. That ability turns the creature into a colored, endlessly recyclable sacrifice target that supplies the shape of a loop without supplying any payoff of its own. Feed it to an aristocrat outlet, buy it back at your leisure, sacrifice it again: the value lives in the triggers on either end, never in the bug. Because it returns only itself, and only to hand rather than the battlefield, there is no board flood and no free engine to break. You get one bug back per activation, replayed for two mana, at whatever pace your mana can afford. That single-target, self-only, deliberately overpriced return is the ceiling built into the card: it cannot mass-recur a graveyard, cannot loop for free, cannot do anything except come back one more time when you pay. Its role is structural, not statistical. It brings a repeatable fuel source; it asks the deck around it to bring the reason that fuel is worth burning.