Sarkhan, Wanderer to Shiv

A digital-only planeswalker built around a mechanic that could never survive on cardboard: perpetual effects that rewrite a card's cost permanently, not just the turn you cast them. The first plus is the engine. Feed Dragon cards a lasting discount and, more radically, an alternative cost of equal to their mana value, and a hand of expensive fatties becomes a hand of things you can pay for with generic mana off any color source. That second clause is the sleeper: it decouples big Dragons from their color requirements, so a pile of the format's best flyers can be cast off whatever lands happen to be untapped, regardless of what they demand in their own casting cost. The other two abilities keep the engine fed and defend it. The second plus conjures a Shivan Dragon directly into your hand, so the cost-rewriting plus can generate its own targets even from an empty grip, while the minus keeps a blocker off the board without ever needing to build toward a finisher. What separates this Sarkhan from the many cost-reducers before it is the direction of the discount: it does not touch the battlefield or the stack the way most planeswalkers do, but the contents of your hand, retroactively and durably. That kind of persistent state-tracking across an entire game is precisely what a paper card cannot police, and it points at how differently a Sarkhan can be built when the ink does not have to enforce itself.