Befoul

The double duty is the design point. Most removal of this era picked a lane: Stone Rain hitting lands, a kill spell hitting creatures, each demanding a deck slot committed to one job. This collapses both targets into a single sorcery, so a card that would otherwise rot in hand against the wrong board usually has something to point at. Four mana to destroy one permanent is steep next to the era's premium kills, and the nonblack clause walls off the obvious mirror-match use, but the breadth pays for the rate: against a screwed opponent it is land destruction, against a flooded one it is creature removal, and which job it does is a decision deferred to cast rather than fixed at deckbuilding. The regeneration-proof clause closes the loophole that mattered most when this kind of card was new, when regenerators and dedicated blockers could otherwise shrug off a kill spell for free. What it cannot touch defines it as sharply as what it can: artifacts, enchantments, planeswalkers, and every black creature stand outside its reach, so the flexibility lives entirely within the land-or-nonblack-creature window. Inside that window it rarely sits dead; outside it, it does nothing at all. The games where it stays in hand are the ones where the opponent committed to permanents it was never built to answer.