Leyline of Resonance

If this card is in your opening hand, you may begin the game with it on the battlefield.
Whenever you cast an instant or sorcery spell that targets only a single creature you control, copy that spell. You may choose new targets for the copy.

Cursed Mirror

{T}: Add {R}.
As this artifact enters, you may have it become a copy of any creature on the battlefield until end of turn, except it has haste.

Essence Flux

Exile target creature you control, then return that card to the battlefield under its owner's control. If it's a Spirit, put a +1/+1 counter on it.

Copy Land

You may have this enchantment enter as a copy of any land on the battlefield, except it's an enchantment in addition to its other types.

Blur

Exile target creature you control, then return that card to the battlefield under its owner's control.
Draw a card.

Ghostly Flicker

Exile two target artifacts, creatures, and/or lands you control, then return those cards to the battlefield under your control.

Gandalf the Grey

Whenever you cast an instant or sorcery spell, choose one that hasn't been chosen —
• You may tap or untap target permanent.
• Gandalf deals 3 damage to each opponent.
• Copy target instant or sorcery spell you control. You may choose new targets for the copy.
• Put Gandalf on top of its owner's library.