Xorn

If you would create one or more Treasure tokens, instead create those tokens plus an additional Treasure token.

Captain Lannery Storm

Haste
Whenever Captain Lannery Storm attacks, create a Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")
Whenever you sacrifice a Treasure, Captain Lannery Storm gets +1/+0 until end of turn.

Liquimetal Torque

{T}: Add {C}.
{T}: Target nonland permanent becomes an artifact in addition to its other types until end of turn.

Arcane Signet

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

Simian Spirit Guide

Exile Simian Spirit Guide from your hand: Add {R}.

Thought Vessel

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

Prismatic Lens

{T}: Add {C}.
{1}, {T}: Add one mana of any color.

Sol Ring

Unexpected Windfall

As an additional cost to cast this spell, discard a card.
Draw two cards and create two Treasure tokens. (They're artifacts with "{T}, Sacrifice this artifact: Add one mana of any color.")

Seize the Spoils

As an additional cost to cast this spell, discard a card.
Draw two cards and create a Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")

Etali, Primal Storm

Whenever Etali, Primal Storm attacks, exile the top card of each player's library, then you may cast any number of spells from among those cards without paying their mana costs.