Yanling's Harbinger

One search target, hardcoded by name: this Bird finds Mu Yanling, Celestial Wind and nothing else. That single-name lock is what makes the design unusual. Most blue creature tutors pull from a broad category (an instant, an artifact, whatever the controller wants at a cost); here the search is welded to one planeswalker, which turns the card into a consistency engine rather than a flexible toolbox. The graveyard clause is the part doing real work: because it can search the yard as well as the library, a Mu Yanling that got countered, discarded, or milled is recoverable, so the two-card pair behaves almost like a four-copy planeswalker package. The 2/4 flying body is defensive by intent, not threatening: it walls off the early aggression a five-drop search creature would otherwise fold to, buying the time for the planeswalker it just retrieved to start ticking. That pairing (an evasive blocker plus guaranteed access to a specific bomb, even one already dead once) is the entire point. The card is not built to win on its stats; it exists to fetch a particular planeswalker into hand whenever it enters the battlefield. Remove the named target and there is no card left; the identity is wholly in service to Mu Yanling.