Bender's Waterskin

The premium the color-fixing mana rock always pays is the tempo hit of coming down tapped, or the deckbuilding cost of a strict color restriction. This one takes a different tack: it fixes for any color, but it also untaps during every other player's untap step, quietly multiplying its output across a full turn cycle. That clause is the whole reason it exists, and it rewards holding mana up outside your own turn. Even against a single opponent it untaps on their untap step, handing you a fresh activation for instants or flash cards; add more opponents and each of their untap steps hands you another, mana you can spend on instant-speed interaction, flash threats, or an untap-window combo piece held up across the table. The design lineage here is the untap-on-others'-turns rock, a class that has always leaned on having other turns to exploit: stronger the more opponents there are. What makes this one worth a second look is the unconditional any-color output stapled to it, folding fixing and off-turn ramp into a single slot that most such artifacts split between two cards. It rewards a build that actually wants to act on other players' turns; parked in a deck that only ever spends mana on its own turn, the extra untaps go to waste.