Double Stroke

Hidden agenda (Start the game with this conspiracy face down in the command zone and secretly choose a card name. You may turn this conspiracy face up any time and reveal that name.)
Whenever you cast an instant or sorcery spell with the chosen name, you may copy it. You may choose new targets for the copy.

Backup Plan

(Start the game with this conspiracy face up in the command zone.)
Draw an additional hand of seven cards as the game begins. Before taking mulligans, shuffle all but one of your hands into your library.

Omniscience

You may cast spells from your hand without paying their mana costs.

Black Lotus

{T}, Sacrifice Black Lotus: Add three mana of any one color.

Teferi, Mage of Zhalfir

Flash
Creature cards you own that aren't on the battlefield have flash.
Each opponent can cast spells only any time they could cast a sorcery.

Leyline of Anticipation

If Leyline of Anticipation is in your opening hand, you may begin the game with it on the battlefield.
You may cast spells as though they had flash.