Solemn Simulacrum

When this creature enters, you may search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.
When this creature dies, you may draw a card.

Midnight Clock

{T}: Add {U}.
{2}{U}: Put an hour counter on Midnight Clock.
At the beginning of each upkeep, put an hour counter on Midnight Clock.
When the twelfth hour counter is put on Midnight Clock, shuffle your hand and graveyard into your library, then draw seven cards. Exile Midnight Clock.

Mirror Box

The "legend rule" doesn't apply to permanents you control.
Each legendary creature you control gets +1/+1.
Each nontoken creature you control gets +1/+1 for each other creature you control with the same name as that creature.

Saheeli, the Gifted

+1: Create a 1/1 colorless Servo artifact creature token.
+1: The next spell you cast this turn costs {1} less to cast for each artifact you control as you cast it.
−7: For each artifact you control, create a token that's a copy of it. Those tokens gain haste. Exile those tokens at the beginning of the next end step.
Saheeli, the Gifted can be your commander.