Tarkir: Dragonstorm Commander

Legendary Creature — Human Spirit Dragon

Flying, vigilance
Flurry — Whenever you cast your second spell each turn, copy that spell if it targets a permanent or player, and you may choose new targets for the copy. If you don't copy a spell this way, draw a card.

Shiko and Narset, Unified

Aligned Heart

Monk

Enchantment

Flurry — Whenever you cast your second spell each turn, put a rally counter on this enchantment. Then create a 1/1 white Monk creature token with prowess for each rally counter on it. (Whenever you cast a noncreature spell, the token gets +1/+1 until end of turn.)

Tarkir: Dragonstorm

Creature — Human Monk

Flurry — Whenever you cast your second spell each turn, put a +1/+1 counter on this creature. Scry 1. (Look at the top card of your library. You may put that card on the bottom.)

Poised Practitioner

Tarkir: Dragonstorm Promos

Taigam, Master Opportunist

Copy

Legendary Creature — Human Monk

Flurry — Whenever you cast your second spell each turn, copy it, then exile the spell you cast with four time counters on it. If it doesn't have suspend, it gains suspend. (At the beginning of its owner's upkeep, they remove a time counter. When the last is removed, they may play it without paying its mana cost. If it's a creature, it has haste.)

Creature — Orc Monk

When this creature enters, return target nonland permanent card with mana value 2 or less from your graveyard to your hand.
Flurry — Whenever you cast your second spell each turn, tap target creature an opponent controls.

Wayspeaker Bodyguard

Cori-Steel Cutter

Artifact — Equipment

Equipped creature gets +1/+1 and has trample and haste.
Flurry — Whenever you cast your second spell each turn, create a 1/1 white Monk creature token with prowess. You may attach this Equipment to it. (Whenever you cast a noncreature spell, the token gets +1/+1 until end of turn.)
Equip {1}{R}

Bird

Flying
Flurry — Whenever you cast your second spell each turn, create a 1/1 white Bird creature token with flying.

Wingblade Disciple

Creature — Goblin Monk

Haste
Flurry — Whenever you cast your second spell each turn, this creature deals 1 damage to each opponent.

Devoted Duelist

Creature — Dog Monk

When this creature enters, exile the top card of your library. Until the end of your next turn, you may play that card.
Flurry — Whenever you cast your second spell each turn, this creature gains double strike until end of turn.

Equilibrium Adept

Flurry — Whenever you cast your second spell each turn, this creature gets +1/+1 until end of turn.
{1}: Add {U}, {R}, or {W}. Activate only once each turn.

Jeskai Devotee

Flurry — Whenever you cast your second spell each turn, this creature deals 2 damage to each opponent and you gain 2 life.