Command Tower

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

Jarad, Golgari Lich Lord

Jarad gets +1/+1 for each creature card in your graveyard.
{1}{B}{G}, Sacrifice another creature: Each opponent loses life equal to the sacrificed creature's power.
Sacrifice a Swamp and a Forest: Return this card from your graveyard to your hand.

Arcane Signet

Old Stickfingers

When you cast this spell, reveal cards from the top of your library until you reveal X creature cards. Put all creature cards revealed this way into your graveyard, then put the rest on the bottom of your library in a random order.
Old Stickfingers's power and toughness are each equal to the number of creature cards in your graveyard.

Sol Ring

Lord of Extinction

Lord of Extinction's power and toughness are each equal to the number of cards in all graveyards.

Angel of Suffering

Flying
If damage would be dealt to you, prevent that damage and mill twice that many cards.