Arcane Signet

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

Zaxara, the Exemplary

Deathtouch
{T}: Add two mana of any one color.
Whenever you cast a spell with {X} in its mana cost, create a 0/0 green Hydra creature token, then put X +1/+1 counters on it.

Exotic Orchard

{T}: Add one mana of any color that a land an opponent controls could produce.

Opulent Palace

This land enters tapped.
{T}: Add {B}, {G}, or {U}.

Cultivate

Search your library for up to two basic land cards, reveal those cards, put one onto the battlefield tapped and the other into your hand, then shuffle.

Command Tower

Villainous Wealth

Target opponent exiles the top X cards of their library. You may cast any number of spells with mana value X or less from among them without paying their mana costs.