Ophidian Eye

Curiosity gave blue a one-mana version of this trick a few years earlier, and the design lineage runs straight through it: enchant a creature, turn its damage to an opponent into card draw, and ride the loop. The crucial word is damage, not combat damage, and that is where the card finds its truest home. Pair it with a creature that can deal damage to a player at will (Niv-Mizzet, the Firemind being the canonical partner, flinging a point at a face and refilling the hand each time) and the draw clause becomes a one-card-pays-itself engine that does not need a combat step at all; with the right untap or mana-doubling, it loops into a deck. On an evasive attacker it is humbler but reliable: a body that keeps connecting becomes a refill spell every turn. The two extra generic over the cheaper original all go to flash, which changes the deployment math. Instead of committing the Aura on your own turn and telegraphing the plan a full turn ahead, you leave the mana up and deploy it at instant speed: in combat, that means slapping it onto an unblocked attacker during the declare-blockers step, so the enchantment resolves before the combat damage step and the trigger lands that same turn. What flash cannot solve is the Aura tax itself: enchant a creature, watch it die to removal before it has dealt any damage, and you are down three mana and a card. The instant speed buys you a safer window, not immunity.