Command Tower

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

Kaervek the Merciless

Whenever an opponent casts a spell, Kaervek the Merciless deals damage equal to that spell's mana value to any target.

Luxury Suite enters tapped unless you have two or more opponents.
{T}: Add {B} or {R}.

Lands you control have "{T}: Add one mana of any color."
{T}: Add one mana of any color.

Dragonskull Summit enters tapped unless you control a Swamp or a Mountain.
{T}: Add {B} or {R}.

{T}: Add one mana of any color in your commander's color identity.
Sacrifice Commander's Sphere: Draw a card.

Fire Diamond enters tapped.
{T}: Add {R}.

Haunted Ridge enters tapped unless you control two or more other lands.
{T}: Add {B} or {R}.

({T}: Add {B} or {R}.)
Smoldering Marsh enters tapped unless you control two or more basic lands.

Charcoal Diamond enters tapped.
{T}: Add {B}.

Training Center enters tapped unless you have two or more opponents.
{T}: Add {U} or {R}.