Reknit

Regeneration almost never travels as a standalone instant: the mechanic spent most of its life stapled to a body or burned off a creature's own activated ability, where the shield was tethered to something already on the battlefield. Stripping the effect down to a clean two-mana protective spell, payable with green or white in any combination, is the whole conceit. The choice to target "permanent" rather than "creature" is the genuine quirk. Regeneration as a keyword only ever matters to things that are destroyed and can be regenerated, so the broader wording mostly future-proofs against odd cases rather than expanding the card in practice; still, an artifact or enchantment staring down destruction can be saved exactly as a creature can. As combat-trick math it does what a thousand protective instants do, trading one card to blank a removal spell or an ugly block. What sets it apart from indestructibility or a flash blocker is the route it takes: the oldest defensive mechanic in the game, sold loose, paid for in whichever of two colors your board happens to produce.