Bespoke Battlewagon

Most energy payoffs assume a spread of cards generating and spending the resource across a whole deck; this one closes the loop inside a single card. The first tap produces the fuel, and three separate sinks spend it: two energy to tap an attacker, three to draw, four to animate the wagon into a creature that swings on its own. That self-sufficiency is what sets it apart from the rest of the mechanic. It never needs a supporting cast to matter, and it never needs to attack to earn its slot. Most Vehicles are dead weight when you have no creatures to crew them, which is the design problem this one sidesteps entirely: a Vehicle whose most valuable turn might be one where it just sits and taps. Crew 4 and the four-energy animation cost are the ceiling the design puts on the body. A 5/6 for four mana that also drew cards, tapped down blockers, and attacked for free would be indefensible, so combat access is gated behind either committing creatures to crew or banking enough energy to bring it online. The energy costs escalate cleanly, which turns each turn into a small budgeting decision: cash in now for the cheaper effect, or hold and pool toward the more expensive one. It wants a blue utility deck that values a resilient standalone engine more than one wedded to the energy theme, which is an unusual role for an energy card to fill.