Marshal of Zhalfir

Other Knights you control get +1/+1.
{W}{U}, {T}: Tap another target creature.

Pyroblast

Choose one —
• Counter target spell if it's blue.
• Destroy target permanent if it's blue.

Vertex Paladin

Flying
Vertex Paladin's power and toughness are each equal to the number of creatures you control.

Invasion of Xerex

(As a Siege enters, choose an opponent to protect it. You and others can attack it. When it's defeated, exile it, then cast it transformed.)
When Invasion of Xerex enters the battlefield, return up to one target creature to its owner's hand.

Invasion of Xerex // Vertex Paladin

Daze

You may return an Island you control to its owner's hand rather than pay this spell's mana cost.
Counter target spell unless its controller pays {1}.

Xerex Strobe-Knight

Flying, vigilance
{T}: Create a 2/2 white and blue Knight creature token with vigilance. Activate only if you've cast two or more spells this turn.

Skyknight Vanguard

Flying
Whenever Skyknight Vanguard attacks, create a 1/1 white Soldier creature token that's tapped and attacking.

Swords to Plowshares

Exile target creature. Its controller gains life equal to its power.

Izzet Charm

Choose one —
• Counter target noncreature spell unless its controller pays {2}.
• Izzet Charm deals 2 damage to target creature.
• Draw two cards, then discard two cards.

Island

Expressive Iteration

Look at the top three cards of your library. Put one of them into your hand, put one of them on the bottom of your library, and exile one of them. You may play the exiled card this turn.

Belenon War Anthem

Invasion of Belenon

(As a Siege enters, choose an opponent to protect it. You and others can attack it. When it's defeated, exile it, then cast it transformed.)
When Invasion of Belenon enters the battlefield, create a 2/2 white and blue Knight creature token with vigilance.

Invasion of Belenon // Belenon War Anthem

Counterspell

Mystic Monastery

Mystic Monastery enters the battlefield tapped.
{T}: Add {U}, {R}, or {W}.

Inspiring Veteran

Dovin's Veto

This spell can't be countered.
Counter target noncreature spell.

Stern Scolding

Counter target creature spell with power or toughness 2 or less.