Ruric Thar, the Unbowed

A symmetrical tax that punishes the player most equipped to evade it. The 6-damage trigger fires on every noncreature spell anyone casts, which sounds like a Manabarbs-style group-slug effect, but the design is sharper than that: it falls hardest on the very decks that want to live in instants, removal, and combo pieces, while the creature-heavy strategies that share its colors barely notice. The forced-attack clause is the price for the body. Wizards gave it a 6/6 with vigilance and reach (a wall and a clock at once), then made it swing every turn it can, so the threat that hoses spellcasting cannot also sit back as an untouchable lock piece. You are committing to the red zone whether you like it or not, which keeps the card from being purely oppressive. The flavor lines up with the build: a one-creature anti-magic crusade who would rather break a face than respect a stack. Its lineage runs through the lock-creature tradition, the bodies that turn a noncreature-heavy plan into a self-inflicted wound, but most of those (Gaddock Teeg, Eidolon of Rhetoric) work by denial. This one works by deterrence and damage, daring you to cast the spell anyway and pay six life for the privilege.