Rowan's Battleguard

A conditional payoff with a very specific price of admission: the +3/+0 is free, but only if you already have a Rowan planeswalker on the battlefield to fuel it. That turns a workmanlike 3/3 first striker into a 6/3 that trades up and races over blockers, and it explains the whole build. The card is not designed to be good in a vacuum; it is designed to make you want the specific planeswalker it names, a piece of top-down synergy that ties a common-rarity beater to a legendary character's presence. Without the anchor it is a fair-if-unexciting body, first strike keeping it relevant in combat but nothing more. With the anchor it hits like a card two mana above its rate. The design lives entirely in that gap, and the reward for closing it (an aggressive first striker that punishes chumps and pressures the opponent while the planeswalker ticks) is generous enough to justify the deckbuilding demand it makes. This is the "control the named character, get better" school of creature design, where the payoff is calibrated against how hard the condition is to meet rather than against the creature's own stats.