2) Tokens that look too similar If your Treasure and Clue share the same art, frame, and color, you will tap the wrong one
Though its a pricey (in real dollars) ask, Lions Eye Diamond and Auriok Salvagers will give you not only infinite mana, but infinite 2/2 Necron Warriors

Preston Blink | Commander | Paige Smith Commander (1) 1 Preston, the Vanisher Creatures (30) 1 Blade Splicer 1 Captain of the Watch 1 Charming Prince 1 Distinguished Conjurer 1 Felidar Guardian 1 Fiend Hunter 1 Gallant Cavalry 1 Inspiring Overseer 1 Knight of the White Orchid 1 Kor Cartographer 1 Mage's Attendant 1 Meteor Golem 1 Palace Jailer 1 Pegasus Guardian 1 Priest of Ancient Lore 1 Rambunctious Mutt 1 Resolute Reinforcements 1 Restoration Angel 1 Roving Harper 1 Rumor Gatherer 1 Solemn Simulacrum 1 Soul Warden 1 Soul's Attendant 1 Spirited Companion 1 Stonehorn Dignitary 1 Sun Titan 1 Thraben Inspector 1 Wall of Omens 1 Welcoming Vampire 1 White Plume Adventurer Instants (12) 1 Acrobatic Maneuver 1 Cloudshift 1 Cosmic Intervention 1 Ephemerate 1 Flicker of Fate 1 Justiciar's Portal 1 Kabira Takedown // Kabira Plateau 1 Lae'zel's Acrobatics 1 Otherworldly Journey 1 Return to Dust 1 Sejiri Shelter // Sejiri Glacier 1 Swords to Plowshares Sorceries (4) 1 Austere Command 1 Emeria's Call // Emeria, Shattered Skyclave 1 Hour of Reckoning 1 Makindi Stampede // Makindi Mesas Enchantments (8) 1 Anointed Procession 1 Felidar Retreat 1 Flickerform 1 Intangible Virtue 1 Journey to Nowhere 1 Oblivion Ring 1 Teleportation Circle 1 Valor in Akros Artifacts (9) 1 Arcane Signet 1 Conjurer's Closet 1 Heraldic Banner 1 Marble Diamond 1 Mind Stone 1 Oketra's Monument 1 Panharmonicon 1 Skullclamp 1 Sol Ring Truthfully, I'm generally used to seeing my Blink Commander decks being either Bant or Azorius colors more than anything

Cecil, Dark Knight / Cecil, Redeemed Paladin Besides its incredible, flavorful design (FFIV), Cecil, Dark Knight is also a very good black suicide aggro card as a 2/3 deathtouch creature with a little bit of a downside that you can turn into upside later
From a playability standpoint, Arthur is probably my favorite card in all of Rise of the Floodborn, as his ability adds a lot of fun combos and mechanics to the game we didnt have in The First Chapter
Into the Inklands