Surge of Righteousness

The color hate is the whole pitch, and the design knows exactly which enemies it was built to stop. Red and black are the two colors that put creatures into combat early and hard, so a two-mana instant that hits only those colors, only while they're attacking or blocking, is a deliberately surgical answer rather than a general-purpose kill spell. The two restrictions stack into the price: it cannot touch a green beater or a white blocker, and it cannot remove a creature sitting back on defense (or a mana dork that never enters combat). What it does instead is win the trade it was meant for, killing an attacker before damage and banking two life on top, which is precisely the math a white deck wants against the colors that race it. This is the lineage of pointed sideboard removal that white has always carried, the descendant of cards that asked you to know your enemy before the spell did anything: narrow on purpose, dead against the wrong matchup, brutal against the right one. The lifegain is not a throwaway rider here; against aggressive red and black starts, two life is often a full attack step bought back, which turns a removal spell into a tempo-and-clock swing rather than a one-for-one. A clean piece of asymmetric warfare, priced to be efficient only when it is aimed correctly.