While the deck is already good, Mardu (red/white/black) has plenty of useful support cards for the strategy that make it a great base deck to upgrade over time
Esper Charm Esper Charms versatility is surprisingly good, and while it's often used as an instant version of Divination, this charm can be handy when needed to remove enchantments or just deprive your opponents last few cards from their hand
Before we delve into each deck individually, let's talk about the new mini-game for Commander: Bounty cards
Just remember that whichever mode you choose to cast becomes the mana value of the card on the stack and on the battlefield, unlike other, similar built-in cost reduction mechanics like Suspend or Miracle, s o a commander like Yuriko, the Tigers Shadow very much likes Prototype cards, while Vial Smasher the Fierce does not
Theres an infinite mana combo with Dockside Extortionist and Temur Sabertooth