Blinding Souleater

Strip the symbol of its cleverness and what you have left is a recurring Icy Manipulator stapled to a small body: pay the cost, tap a blocker or a mana creature or the threat that wants to swing next turn, repeat at instant speed. The trick is that two life pays the activation just as well as white mana does, which means the creature works identically in a shell running no white at all. A control or artifact deck of any color suddenly fields a repeatable tap-down it could not otherwise run, paid in the currency every deck shares. The cost is real: two life per activation compounds over a long game, and the 1/3 frame is built to grind rather than win, so a Phyrexian-mana payer trades a slow life drain for a hard lock on one creature each turn. The timing is where the work happens, and it has to be done before attackers are declared (during the beginning-of-combat step) to keep a creature out of the swing; tap it after declaration and it stays in combat, just barred from a future attack. Used proactively, it gates an opponent's best attacker on the upkeep or holds a blocker down to crack open a stalled board: the patient, repetitive job artifact decks have always wanted from a cheap permanent.