Reverberating Summons

At the beginning of each combat, if you've cast two or more spells this turn, this enchantment becomes a 3/3 Monk creature with haste in addition to its other types until end of turn.
{1}{R}, Discard your hand, Sacrifice this enchantment: Draw two cards.

Jeskai Devotee

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.

Frostcliff Siege

As this enchantment enters, choose Jeskai or Temur.
• Jeskai — Whenever one or more creatures you control deal combat damage to a player, draw a card.
• Temur — Creatures you control get +1/+0 and have trample and haste.

Effortless Master

Vigilance
Menace (This creature can't be blocked except by two or more creatures.)
This creature enters with two +1/+1 counters on it if you've cast two or more spells this turn.

Taigam, Master Opportunist

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.)

Evolving Wilds

{T}, Sacrifice this land: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

Wingspan Stride

Enchant creature
Enchanted creature gets +1/+1 and has flying.
{2}{U}: Return this Aura to its owner's hand.

Mountain

Skimming Strike

Tap up to one target creature. Draw a card. (Then shuffle this card into its owner's library.)

Dirgur Island Dragon

Flying
Ward {2} (Whenever this creature becomes the target of a spell or ability an opponent controls, counter it unless that player pays {2}.)

Dirgur Island Dragon // Skimming Strike

Mystic Monastery

This land enters tapped.
{T}: Add {U}, {R}, or {W}.

Twin Bolt

Twin Bolt deals 2 damage divided as you choose among one or two targets.

Island

Fresh Start

Flash
Enchant creature
Enchanted creature gets -5/-0 and loses all abilities.

Humbling Elder

Flash
When this creature enters, target creature an opponent controls gets -2/-0 until end of turn.

Fleeting Effigy

Haste
At the beginning of your end step, return this creature to its owner's hand. (Return it only if it's on the battlefield.)
{2}{R}: This creature gets +2/+0 until end of turn.

Devoted Duelist

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