Mental Discipline

The looter, untethered from a body. Most card filtering of the early era arrived stapled to a creature you had to protect or a one-shot spell you cast and lost: this puts the rummage on the battlefield as an enchantment, immune to the kind of combat-step accidents and creature removal that make Merfolk Looter a liability. Free of any timing constraint, it loots on your own end step, in response to a discard-matters trigger, or repeatedly through a turn until the hand looks right. The activation tax does the regulating work: paying mana each cycle keeps the engine from running away, and because you discard before you draw, the swap is card-for-card. You do not net cards, you trade the ones you have for the ones you want. That places it in the lineage of effects that convert flooded lands and dead draws into live action. The discard half is the real lever for the decks that want it: a graveyard engine, or a payoff that rewards being pitched rather than drawn, gets a steady throttle here instead of a single dig. Inert without a reason supplied by the deck around it, it rewards a build that has something to do with the cards it sheds, which is what elevates a cheap, repeatable filtering permanent past the three mana on its face.