Marble Diamond

Marble Diamond enters tapped.
{T}: Add {W}.

Millikin

{T}, Mill a card: Add {C}. (To mill a card, put the top card of your library into your graveyard.)

Sky Diamond

Sol Ring

Fire Diamond

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

Charcoal Diamond

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

Breya, Etherium Shaper

When Breya, Etherium Shaper enters, create two 1/1 blue Thopter artifact creature tokens with flying.
{2}, Sacrifice two artifacts: Choose one —
• Breya deals 3 damage to target player or planeswalker.
• Target creature gets -4/-4 until end of turn.
• You gain 5 life.

Artificer's Assistant

Flying
Whenever you cast a historic spell, scry 1. (Artifacts, legendaries, and Sagas are historic. To scry 1, look at the top card of your library, then you may put that card on the bottom.)