Cloaked Siren

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

Skyspear Cavalry

Flying
Double strike (This creature deals both first-strike and regular combat damage.)

Riptide Chimera

Flying
At the beginning of your upkeep, return an enchantment you control to its owner’s hand.

Spawn of Thraxes

Flying
When Spawn of Thraxes enters the battlefield, it deals damage to any target equal to the number of Mountains you control.

Fleetfeather Cockatrice

Flash (You may cast this spell any time you could cast an instant.)
Flying, deathtouch
: Monstrosity 3. (If this creature isn’t monstrous, put three +1/+1 counters on it and it becomes monstrous.)

Dawnbringer Charioteers

Flying, lifelink
Heroic — Whenever you cast a spell that targets Dawnbringer Charioteers, put a +1/+1 counter on Dawnbringer Charioteers.

Spawn of Thraxes

Flying
When Spawn of Thraxes enters the battlefield, it deals damage to any target equal to the number of Mountains you control.

Dawnbringer Charioteers

Flying, lifelink
Heroic — Whenever you cast a spell that targets Dawnbringer Charioteers, put a +1/+1 counter on Dawnbringer Charioteers.

Jace’s Mindseeker

Flying
When Jace’s Mindseeker enters the battlefield, target opponent mills five cards. You may cast an instant or sorcery spell from among them without paying its mana cost.

Jace’s Phantasm

Flying
Jace’s Phantasm gets +4/+4 as long as an opponent has ten or more cards in their graveyard.

Errant Ephemeron

Flying
Suspend 4— (Rather than cast this card from your hand, you may pay and exile it with four time counters on it. At the beginning of your upkeep, remove a time counter. When the last is removed, cast it without paying its mana cost. It has haste.)

Riftwing Cloudskate

Flying
When Riftwing Cloudskate enters the battlefield, return target permanent to its owner’s hand.
Suspend 3— (Rather than cast this card from your hand, you may pay and exile it with three time counters on it. At the beginning of your upkeep, remove a time counter. When the last is removed, cast it without paying its mana cost. It has haste.)

Phantasmal Dragon

Flying
When Phantasmal Dragon becomes the target of a spell or ability, sacrifice it.

Krovikan Mist

Flying
Krovikan Mist’s power and toughness are each equal to the number of Illusions on the battlefield.

Merfolk Wayfinder

Flying
When Merfolk Wayfinder enters the battlefield, reveal the top three cards of your library. Put all Island cards revealed this way into your hand and the rest on the bottom of your library in any order.

Demigod of Revenge

When you cast this spell, return all cards named Demigod of Revenge from your graveyard to the battlefield.
Flying, haste

Arbiter of the Ideal

Flying
Inspired — Whenever Arbiter of the Ideal becomes untapped, reveal the top card of your library. If it’s an artifact, creature, or land card, you may put it onto the battlefield with a manifestation counter on it. That permanent is an enchantment in addition to its other types.

Shrike Harpy

Flying
Tribute 2 (As this creature enters the battlefield, an opponent of your choice may put two +1/+1 counters on it.)
When Shrike Harpy enters the battlefield, if tribute wasn’t paid, target opponent sacrifices a creature.

Eater of Hope

Flying
, Sacrifice another creature: Regenerate Eater of Hope.
, Sacrifice two other creatures: Destroy target creature.

Forgestoker Dragon

Flying
: Forgestoker Dragon deals 1 damage to target creature. That creature can’t block this combat. Activate this ability only if Forgestoker Dragon is attacking.

Akroan Skyguard

Flying
Heroic — Whenever you cast a spell that targets Akroan Skyguard, put a +1/+1 counter on Akroan Skyguard.

Silent Sentinel

Flying
Whenever Silent Sentinel attacks, you may return target enchantment card from your graveyard to the battlefield.