Oblivion Ring

White's catch-all answer, and the template that nearly every modular "exile a permanent" enchantment since has been cut from. The trick that made it durable is structural: by splitting the work across two triggered abilities (one that exiles on entry, one that returns the card on exit) it answers anything that is not a land while staying an enchantment rather than an instant. That second clause is the cost. The exiled permanent does not die; it sits in exile linked to the ring, so destroying the enchantment hands the card straight back to its owner, often at full value and sometimes with its enters-the-battlefield trigger reloaded. The wording also opens a notorious response window, though not the one most players assume: try to break it by destroying the ring in response to its exile trigger, and the leaves-the-battlefield trigger simply resolves first to no effect (there is nothing exiled to return yet), after which the exile trigger resolves and removes your permanent for good. The clean escape is Disenchant after the dust settles, turning the ring from removal into a liability. None of that has stopped it from being the reference point for flexible white removal; later iterations like Banishing Light tightened the timing and closed the give-it-back loophole, but they were all measured against this shape: cheap, color-defining, and answerable in exactly the ways white removal is supposed to be answerable.