Kami of Fire's Roar
Evasion bolted onto an engine you were already running, rather than a payoff you pay for separately. This sat inside a block built around chaining cheap spells with a shared pedigree, and the Spirit asks only that the spells you cast carry it: every qualifying trick or creature you play forbids a chosen defender from declaring as a blocker. The clever part is the timing. The no-block window opens the moment the triggering spell goes on the stack, well before your declare-attackers step, and the chosen defender stays sidelined whether or not that spell ever resolves; a countered trick still does the work. Cast two such spells and you pin down two blockers, which is how a wide board converts into damage that actually lands: each cast pries open another lane through the defending side. The 2/3 body is deliberately modest because the card was never meant to attack profitably on its own. It is a reward for casting lots of small spells without committing extra slots to that reward, paid out on the offensive axis: a creature that turns tempo into reach. The four-mana cost is the tax the design accepts. A 2/3 that does no immediate work on arrival is steep for the rate, the price for an ability that scales with everything else you are casting rather than asking for any setup of its own.
