Depth Charge Colossus

The Dreadnought creature type carries a specific weight in Magic history: the original Phyrexian Dreadnought promised a monstrous body for almost nothing, then attached a drawback severe enough that players built entire combo shells around sidestepping it. This colossus revives the same bargain in a cleaner idiom. The prototype clause offers a real fork rather than a growth curve: cast it for and it is a 6/6 for good, or pay the full nine for a 9/9, and whichever size you commit to is the size you keep. Both halves inherit the classic dreadnought catch, which is that it will not untap on its own, so any attack that leaves it tapped strands its power on the battlefield doing nothing. The untap ability is the release valve, turning the card into a mana sink that rewards a board with surplus lands more than a clean curve-out. What makes the design pull in two directions is how the discount and the untap tax time out against each other: the 6/6 wants to hit early, precisely when paying a turn to keep it swinging is hardest to afford, while the 9/9 comes down late enough that the untap fee is trivial. The two modes fail and succeed in opposite phases of the game, a subtler tension than a raw 9/9 for nine usually gets to carry.