Whenever you cast an instant or sorcery spell from your hand, you may cast up to one target card of the other type from your graveyard. If a spell cast from your graveyard this way would be put into your graveyard, exile it instead. Choose a Background (You can have a Background as a second commander.)

This land enters tapped. When this land enters, exile target player's graveyard. {T}: Add {B}.

As this land enters, you may reveal an Island or Swamp card from your hand. If you don't, this land enters tapped. {T}: Add {U} or {B}.

{T}: Add one mana of any color in your commander's color identity.

{1}, {T}: Add {U}{B}.

This land enters tapped. When this land enters, return a land you control to its owner's hand. {T}: Add {U}{B}.

This land enters tapped unless you control an Island or a Swamp. {T}: Add {U} or {B}.

This land enters tapped unless you control two or more other lands. {T}: Add {U} or {B}.

({T}: Add {U} or {B}.) This land enters tapped unless you control two or more basic lands.

{T}: Add {C}. {T}: Add {U} or {B}. Activate only if you control a Swamp.

This land enters tapped. When this land enters, scry 1. (Look at the top card of your library. You may put that card on the bottom.) {T}: Add {U} or {B}.

{T}: Add one mana of any color in your commander's color identity.

Add {B}{B}{B}.

{1}, {T}: Add {U}{B}.

Flying, trample {B}, Sacrifice another creature: Target player mills three cards. Pay 1 life: Add {C}. Spend this mana only to cast a spell from your graveyard.