Ceta Sanctuary

Blue almost never shares a deck with red and green, the two colors furthest from its temperament, and that antipathy is exactly the cost this enchantment is built to charge. Control one of red or green and you get an upkeep loot every turn; control both and the trigger upgrades to a net-positive draw. The structure follows the same gradient that ran through this whole wedge of enemy-color designs: reward partial commitment a little, full commitment more. But here the gradient reads almost like a dare, asking a blue control shell to splash into the colors it has the least reason to touch. The effect itself is modest. As an upkeep loot it smooths draws, feeds a graveyard, and trades excess lands for action, never generating raw card advantage until you clear the higher bar of holding both off-colors at once. What it represents is one of the era's hardest commitments to enemy-color identity as a deckbuilding premise: rather than routing around the friction between blue and the red-green pair, the card treats that friction as the price of admission, paying you in filtering for a partial splash and in genuine advantage for going all the way.