Mechtitan Core

Assemble five: that is the pitch, and the card knows exactly which childhood it is quoting. The activated ability is the whole ritual dressed as a Vehicle: pay five, exile this plus four other artifact creatures or Vehicles, and fold them into a single legendary 10/10 wearing every relevant combat keyword at once (flying, vigilance, trample, lifelink, haste) in all five colors. The design honesty lives in the return clause. The nontoken pieces you fed it come back tapped when Mechtitan leaves, which inverts what a payoff like this usually asks of you. Most cards that eat your permanents trade them away for good; this one only lends them out. That changes the risk math in a specific way: a board wipe answering the token is not a blowout against you, because the exiled pieces return to the battlefield after the sweep resolves, arriving on an empty board. The token itself has no protection, so a single targeted removal spell kills it clean; the consolation is that the removal buys back your army rather than burying it. You have not spent your board, you have compressed it into one profile, and even losing that profile hands the pieces back. The 2/4 crew-2 shell underneath is nearly incidental. This is not a card you cast to attack; it is a button you install and press once the artifacts have accumulated, knowing the exit is as safe as the entry.