Enthusiastic Mechanaut

The cost-reduction line is where the whole design lives: a two-mana flier that shaves the price of every artifact spell you cast afterward is a rate that snowballs, because artifact decks tend to deploy several spells a turn and the discount stacks with each Mechanaut on the board. That makes it less a creature than a soft ritual on legs, converting a body into tempo the longer the game runs. The Goblin Artificer type places it in a long line of cost engines that reward flooding the board with cheap artifacts, though most of that lineage sat squarely in mono-blue affinity shells; splitting the enabler across two colors is the wrinkle, since it ties the discount to a manabase that can support both. The 2/2 flying body is the part that keeps it fragile: it evades on offense and chips in while the artifact count climbs, but it dies to almost anything, so leaning on the discount means committing a soft permanent before the payoff arrives. The tension is familiar to anyone who has built around cost reduction: the reducer is the first thing an opponent wants dead, and its discount arrives too late to help the artifacts you have already cast. What it offers in exchange is a compounding curve, the kind that lets an artifact deck chain two or three spells in a window that would otherwise cost too much, and that is worth a great deal to a deck built to exploit it.