Jin-Gitaxias, Progress Tyrant

Whenever you cast an artifact, instant, or sorcery spell, copy that spell. You may choose new targets for the copy. This ability triggers only once each turn. (A copy of a permanent spell becomes a token.)
Whenever an opponent casts an artifact, instant, or sorcery spell, counter that spell. This ability triggers only once each turn.

Holographic Double

{U}, Exile Holographic Double from your hand: Choose a creature card in your hand. Conjure a duplicate of it into your hand.

Fading Hope

Return target creature to its owner's hand. If its mana value was 3 or less, scry 1. (Look at the top card of your library. You may put that card on the bottom.)

Soulblade Djinn

Flying
Whenever you cast a noncreature spell, creatures you control get +1/+1 until end of turn.

Clone Crafter

When Clone Crafter enters the battlefield, conjure a duplicate of a random creature card from your opponent's library into your hand. It perpetually gains "You may spend mana as though it were mana of any color to cast this spell."

A-Lier, Disciple of the Drowned

Spells can't be countered.
As long as it's your turn, each instant and sorcery card in your graveyard has flashback. The flashback cost is equal to that card's mana cost.

Discover the Formula

Seek three nonland cards, then nonland cards in your hand perpetually gain "This spell costs {1} less to cast."

Oracle of the Alpha

Flying
When Oracle of the Alpha enters, conjure the Power Nine into your library, then shuffle.
Whenever Oracle of the Alpha attacks, scry 1.

A-Thousand-Faced Shadow

Ninjutsu {2}{U} ({2}{U}, Return an unblocked attacker you control to hand: Put this card onto the battlefield from your hand tapped and attacking.)
Flying
When Thousand-Faced Shadow enters from your hand, if it's attacking, create a token that's a copy of another target attacking creature. The token enters tapped and attacking.

Piece It Together

Starting intensity 1
Draw a card. If Piece It Together's intensity is 4, instead take an extra turn after this one.
Cards you own named Piece It Together intensify by 1.