Elminster

Most planeswalkers that draw cards and make tokens are engines you tick up and wait on. This one is a cost-reducer wearing a planeswalker's frame, and the passive is where the design lives. Every scry, whether from the +2 or from any other source in the deck, shaves generic mana off your next instant or sorcery equal to the number of cards you looked at. The discount only touches the generic portion of a cost, so it will not zero out a colored-pip cantrip, but it scales hard on the spells where the generic is the whole point: a big X spell, an overloaded instant, a splashy sorcery whose colored requirement is a single pip. Stack enough scry effects across a turn and that generic reduction compounds until the payoff spell is nearly free. The +2 feeds the loop directly, drawing then scrying two while padding loyalty.

The tension sits between the two halves. The passive wants a deck of scry effects and generic-heavy payoff spells; the -3, live immediately off a starting loyalty of 5, wants raw mana value sitting on top of your library, exiling a high-cost card for a squadron of flying Faerie Dragons. That is real board presence, but it pulls against the spellslinger identity the triggered ability demands, and a single list rarely leans on both. The clause letting Elminster serve as commander is what closes the case: an Azorius spells deck gets a repeatable scry-and-discount engine parked in the command zone, always available and never answered for long.