Recon Craft Theta

Proliferate as an attack trigger is the design idea worth pausing on. Most proliferate lives on enters-the-battlefield triggers or on activated abilities that ask you to sink mana into them each turn; hanging it off a "whenever this attacks" clause turns a counters engine into something that runs itself every combat, so long as you can find two power to crew it. The entry token is the seed: a 0/0 Alien that would die instantly without the +1/+1 counter the Vehicle immediately puts on it, which means the Vehicle staples its own proliferate target to the board so the very first swing has something to grow. From there the loop compounds in every direction counters can point (charge, loyalty, poison, and the humble +1/+1), each getting another the moment this thing connects, or rather the moment it attacks. The 4/4 flying body under crew 2 is deliberately modest, because the card is not selling combat math; it is selling repetition. What ties the payoff to risk is the crew cost itself: the proliferate only fires on the turns you commit power to attacking with it, so the engine cannot grind counters from safety. And because the card is printed as an artifact rather than a creature, it is not a Vehicle in name only when it comes to answers: it sits exposed to artifact removal at any time, crewed or not, which is the pressure valve on a permanent that would otherwise snowball unchecked.