Command Tower

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

Reliquary Tower

You have no maximum hand size.
{T}: Add {C}.

Gruul Turf

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

Simic Growth Chamber

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

Borborygmos and Fblthp

Whenever Borborygmos and Fblthp enters or attacks, draw a card, then you may discard any number of land cards. When you discard one or more cards this way, Borborygmos and Fblthp deals twice that much damage to target creature.
{1}{U}: Put Borborygmos and Fblthp into its owner's library third from the top.

Izzet Boilerworks

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