If youre looking to make infinite mana, youll have to find a permanent that can instantly refund its casting cost plus , and I can only realistically see that happening with Dockside Extortionist
5+ Rare or Mythic Rare cards
Fierce Guardianship from Timeless Wisdom is the most expensive card ($45) in any of this years decks, followed by Deflecting Swat in Arcane Maelstrom ($26), and Deadly Rollick in Enhanced Evolution ($16)
Being a 1/4 also positions this to block quite well
Put the rest on the bottom in a random order.) Legendary Artifact Iraxxa, Empress of Mars Trample Battle cry (Whenever this creature attacks, each other attacking creature gets +1/+0 until end of turn.) Paradox Whenever you cast a spell from anywhere other than your hand, create a 2/2 red Alien Warrior creature token
Just be aware that your opponent gets a consolation prize for each of them