Have

Mindslaver

{4}, {T}, Sacrifice Mindslaver: You control target player during that player's next turn. (You see all cards that player could see and make all decisions for the player.)

Don't Have

Memnarch

{1}{U}{U}: Target permanent becomes an artifact in addition to its other types. (This effect lasts indefinitely.)
{3}{U}: Gain control of target artifact. (This effect lasts indefinitely.)

Diligent Excavator

Whenever you cast a historic spell, target player mills two cards. (Artifacts, legendaries, and Sagas are historic.)

Need for Speed

Sacrifice a land: Target creature gains haste until end of turn.

Xorn

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

Chromatic Orrery

You may spend mana as though it were mana of any color.
{T}: Add {C}{C}{C}{C}{C}.
{5}, {T}: Draw a card for each color among permanents you control.

Minamo, School at Water's Edge

{T}: Add {U}.
{U}, {T}: Untap target legendary permanent.

Tamiyo's Journal

At the beginning of your upkeep, investigate. (Create a Clue token. It's an artifact with "{2}, Sacrifice this artifact: Draw a card.")
{T}, Sacrifice three Clues: Search your library for a card, put that card into your hand, then shuffle.

Umezawa's Jitte

Whenever equipped creature deals combat damage, put two charge counters on Umezawa's Jitte.
Remove a charge counter from Umezawa's Jitte: Choose one —
• Equipped creature gets +2/+2 until end of turn.
• Target creature gets -1/-1 until end of turn.
• You gain 2 life.
Equip {2}

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.

Karlach, Fury of Avernus

Whenever you attack, if it's the first combat phase of the turn, untap all attacking creatures. They gain first strike until end of turn. After this phase, there is an additional combat phase.
Choose a Background (You can have a Background as a second commander.)

Okina, Temple to the Grandfathers

{T}: Add {G}.
{G}, {T}: Target legendary creature gets +1/+1 until end of turn.

Throne of the God-Pharaoh

At the beginning of your end step, each opponent loses life equal to the number of tapped creatures you control.

That Which Was Taken

{4}, {T}: Put a divinity counter on target permanent other than That Which Was Taken.
Each permanent with a divinity counter on it has indestructible.

Bitterthorn, Nissa's Animus

Living weapon (When this Equipment enters, create a 0/0 black Phyrexian Germ creature token, then attach this to it.)
Equipped creature gets +1/+1.
Whenever equipped creature attacks, you may search your library for a basic land card, put it onto the battlefield tapped, then shuffle.
Equip {3}

Epicenter

Target player sacrifices a land of their choice.
Threshold — Each player sacrifices all lands they control instead if seven or more cards are in your graveyard.

Forsaken Monument

Colorless creatures you control get +2/+2.
Whenever you tap a permanent for {C}, add an additional {C}.
Whenever you cast a colorless spell, you gain 2 life.

Akroma's Memorial

Creatures you control have flying, first strike, vigilance, trample, haste, and protection from black and from red.