Narset Transcendent

Six starting loyalty tells you the plan before you read a word of the abilities: she expects to defend herself with card advantage, not with bodies. The +1 is a filter tuned to the deck it belongs in, digging only into noncreature, nonland cards and quietly passing over the creatures and lands a dedicated spellslinger isn't leaning on. The signature is the −2, and its timing is the subtle part: the ability has to resolve first, and only then does the next instant or sorcery you cast from hand that turn pick up rebound automatically. There's no choosing on the stack and no waiting a turn to decide; the moment the ability resolves, the next qualifying spell is committed, so sequencing matters. Cast the −2 with an empty hand or nothing worth doubling and the loyalty is simply spent. The reward, when the hand cooperates, is a spell that resolves, exiles itself, and comes back free on your upkeep: a doubled draw spell, or the same board-altering sorcery landing across two consecutive turns for a single card. The ultimate hangs a wall over the whole opposing spellbook, locking out every noncreature spell an opponent might cast, which decides a slow control game outright if it ever resolves. The through-line is patience: a walker built for the draw-go end of blue-white, accruing an edge that compounds when the next instant or sorcery you cast can count twice.