Cloud's Limit Break

Every mode punishes the same thing: creatures that have already tapped, whether to attack or to fire off an ability. That single requirement is what turns this from raw removal into a tempo trap, rewarding you for baiting an alpha strike, letting an opponent commit their board, then answering on the back half of the turn. The tiered structure lets one card scale with the board rather than with your wallet. Cross-Slash for no extra mana is the cheapest rate a two-mana instant can offer against a single tapped attacker. Blade Beam widens the same effect into a political weapon: it only hits creatures with different controllers, so it clears one dangerous permanent off each of several opponents in a single cast rather than blowing out one board. Omnislash pays a full white spell's worth on top to become a near-symmetrical wrath, catching everything already tapped, including your own commitments. What makes the tiered keyword do real work is that none of the three modes ever escape the tapped requirement; you never break the fiction that these are answers to aggression, only escalations of the same answer. You are not choosing between three different spells. You are choosing how much of a mass attack you want to punish, and paying accordingly.