Arc Reactor

Improvise and mana rocks pull in opposite directions, and this design leans into the contradiction. A rock that produces three colorless is normally the payoff for spending mana up front; here the printed cost is five, but every artifact you tap during casting shaves a generic off the bill, so a board of trinkets can float this into play for a fraction of the number on it. The catch is the tapped-on-entry clause: the turn you assemble it with improvise, it produces nothing, and it drains the very artifacts you would have used for their own effects. That delay is what keeps a three-colorless burst engine from arriving free and firing immediately. What it really wants is a wide artifact base already built for other reasons, a shell where tapping down to five permanents to deploy the rock costs you little because those permanents were not doing much that turn anyway. Once it untaps, three colorless from a single tap is a genuinely large hit, the kind of number that fuels colorless-hungry payoffs and go-wide artifact strategies. The design sits in a specific niche: not a ramp piece for a fair curve, but a compounding-returns engine for a deck that has already committed to flooding the board with cheap artifacts and now needs somewhere to convert that width back into mana.