Mudslide

Most red board-stallers tax attacking or punish creatures for living; this one attacks the untap step itself, the phase almost nothing else in the game touches. Grounded creatures simply do not stand back up unless their controller pays per creature every upkeep, a recurring ransom that has to be re-paid each turn. The asymmetry is the entire pitch: fliers untap for free, so the deck that wants this effect wants an evasive clock floating above the lock everyone else is fighting. That turns a global enchantment into a soft prison piece, useful only to the side that has already broken its own symmetry. The per-creature toll is also what keeps it short of a hard lock: a player with mana to spare can free whichever attackers or blockers they choose, so fat ground decks grind to a crawl while keeping an escape valve open. It comes from the era when red was being handed enchantments meant to police the battlefield without dealing a point of damage, an odd seat for the color to occupy. The mechanic survives mostly as a curiosity and a build-around for fliers and untap-cost trickery, where the -to-untap clause becomes a resource drain nobody else at the table budgeted for.