Cloudthresher

Flash
Reach
When Cloudthresher enters the battlefield, it deals 2 damage to each creature with flying and each player.
Evoke (You may cast this spell for its evoke cost. If you do, it’s sacrificed when it enters the battlefield.)

Affa Guard Hound

Flash (You may cast this spell any time you could cast an instant.)
When Affa Guard Hound enters the battlefield, target creature gets +0/+3 until end of turn.

Bonds of Quicksilver

Flash (You may cast this spell any time you could cast an instant.)
Enchant creature
Enchanted creature doesn’t untap during its controller’s untap step.

Deceiver Exarch

Flash (You may cast this spell any time you could cast an instant.)
When Deceiver Exarch enters the battlefield, choose one —
• Untap target permanent you control.
• Tap target permanent an opponent controls.

Cloaked Siren

Flash (You may cast this spell any time you could cast an instant.)
Flying

Stunt Double

Flash
You may have Stunt Double enter the battlefield as a copy of any creature on the battlefield.

Hollowhenge Spirit

Flash (You may cast this spell any time you could cast an instant.)
Flying
When Hollowhenge Spirit enters the battlefield, remove target attacking or blocking creature from combat.

Drownyard Behemoth

Flash (You may cast this spell any time you could cast an instant.)
Emerge (You may cast this spell by sacrificing a creature and paying the emerge cost reduced by that creature’s converted mana cost.)
Drownyard Behemoth has hexproof as long as it entered the battlefield this turn.

Elder Deep-Fiend

Flash
Emerge (You may cast this spell by sacrificing a creature and paying the emerge cost reduced by that creature’s converted mana cost.)
When you cast this spell, tap up to four target permanents.

Heron’s Grace Champion

Flash
Lifelink
When Heron’s Grace Champion enters the battlefield, other Humans you control get +1/+1 and gain lifelink until end of turn.

Spontaneous Mutation

Flash
Enchant creature
Enchanted creature gets -X/-0, where X is the number of cards in your graveyard.

Spell Queller

Flash
Flying
When Spell Queller enters the battlefield, exile target spell with converted mana cost 4 or less.
When Spell Queller leaves the battlefield, the exiled card’s owner may cast that card without paying its mana cost.

Heron’s Grace Champion

Flash
Lifelink
When Heron’s Grace Champion enters the battlefield, other Humans you control get +1/+1 and gain lifelink until end of turn.

Drogskol Shieldmate

Flash (You may cast this spell any time you could cast an instant.)
When Drogskol Shieldmate enters the battlefield, other creatures you control get +0/+1 until end of turn.

Heron’s Grace Champion

Flash
Lifelink
When Heron’s Grace Champion enters the battlefield, other Humans you control get +1/+1 and gain lifelink until end of turn.

Elder Deep-Fiend

Flash
Emerge (You may cast this spell by sacrificing a creature and paying the emerge cost reduced by that creature’s converted mana cost.)
When you cast this spell, tap up to four target permanents.

Spirit of the Hunt

Flash
When Spirit of the Hunt enters the battlefield, each other creature you control that’s a Wolf or a Werewolf gets +0/+3 until end of turn.

Spirit of the Hunt

Flash
When Spirit of the Hunt enters the battlefield, each other creature you control that’s a Wolf or a Werewolf gets +0/+3 until end of turn.

Swift Spinner

Flash (You may cast this spell any time you could cast an instant.)
Reach (This creature can block creatures with flying.)

Spell Queller

Flash
Flying
When Spell Queller enters the battlefield, exile target spell with converted mana cost 4 or less.
When Spell Queller leaves the battlefield, the exiled card’s owner may cast that card without paying its mana cost.

Nebelgast Herald

Flash (You may cast this spell any time you could cast an instant.)
Flying
Whenever Nebelgast Herald or another Spirit enters the battlefield under your control, tap target creature an opponent controls.

Thunderclap Wyvern

Flash (You may cast this spell any time you could cast an instant.)
Flying
Other creatures you control with flying get +1/+1.

Dualcaster Mage

Flash
When Dualcaster Mage enters the battlefield, copy target instant or sorcery spell. You may choose new targets for the copy.

Snapcaster Mage

Flash
When Snapcaster Mage enters the battlefield, target instant or sorcery card in your graveyard gains flashback until end of turn. The flashback cost is equal to its mana cost. (You may cast that card from your graveyard for its flashback cost. Then exile it.)

Archangel Avacyn // Avacyn, the Purifier

Flash
Flying, vigilance
When Archangel Avacyn enters the battlefield, creatures you control gain indestructible until end of turn.
When a non-Angel creature you control dies, transform Archangel Avacyn at the beginning of the next upkeep.