Sunlance

The color clause is the whole bargain here. Three damage for a single white mana is burn that outpaces almost anything white usually gets to do to a creature, well past the rate of Pacifism or a tapper, and the price for that rate is paid in the target restriction: it can never touch a white creature. White paying for cheap, efficient removal by exempting its own color is an old and deliberate piece of the color pie's logic, the same instinct that hands white conditional spot removal rather than a clean burn spell. The restriction is sharper than it reads, too, because it bites hardest in mirrors and in any meta where white creatures are the threats worth killing; against the things you most want to point it at, it can simply do nothing. Aimed at green, black, red, or blue, though, it kills the overwhelming majority of early and midsized bodies for the price of a single land's worth of mana, ranking among the most efficient creature removal the color has ever been handed. It cleanly illustrates how the pie prices an off-color effect: white gets to borrow red's damage-based kill, but only at a slant that points it away from white's own.