-sigh- Commanders emphasis on color identity in deckbuilding has successfully kept Krrik, Son of Yawgmoth from being a huge problem in the format as a whole, but its still a powerhouse that should be removed or countered on sight against decks with a large or exclusive emphasis on black, as 4 mana can easily become as much as 16, more if life gain enters the equation
Mystic Remora taxes non-creature spells and draws you a ton of cards in the early game when players are casting cheap ramp and tutors
Jolted Awake In the energy deck, Jolted Awake is functionally Reanimate (for only your graveyard)
Alternatively, Altar of Dementia can just win the game with Yedora and Temur Charger
Overgrown Tomb and Llanowar Wastes provide black mana at a cost, and youll lose games because of this without realizing it
Amber/Ruby Single-Player Deck Well examine the Amber/Ruby deck first