Yawgmoth Demon

Flying (This creature can’t be blocked except by creatures with flying or reach.)
First strike (This creature deals combat damage before creatures without first strike.)
At the beginning of your upkeep, you may sacrifice an artifact. If you don’t, tap Yawgmoth Demon and it deals 2 damage to you.

Kjeldoran Skycaptain

Flying; first strike; banding (Any creatures with banding, and up to one without, can attack in a band. Bands are blocked as a group. If any creatures with banding you control are blocking or being blocked by a creature, you divide that creature’s combat damage, not its controller, among any of the creatures it’s being blocked by or is blocking.)

Seraph

Flying
Whenever a creature dealt damage by Seraph this turn dies, put that card onto the battlefield under your control at the beginning of the next end step. Sacrifice the creature when you lose control of Seraph.

Storm Spirit

Flying
: Storm Spirit deals 2 damage to target creature.

Wind Spirit

Flying
Menace (This creature can’t be blocked except by two or more creatures.)

Kjeldoran Skyknight

Flying; first strike; banding (Any creatures with banding, and up to one without, can attack in a band. Bands are blocked as a group. If any creatures with banding you control are blocking or being blocked by a creature, you divide that creature’s combat damage, not its controller, among any of the creatures it’s being blocked by or is blocking.)

Abyssal Specter

Flying
Whenever Abyssal Specter deals damage to a player, that player discards a card.

Illusionary Wall

Defender, flying, first strike
Cumulative upkeep (At the beginning of your upkeep, put an age counter on this permanent, then sacrifice it unless you pay its upkeep cost for each age counter on it.)

Thunder Wall

Defender (This creature can’t attack.)
Flying
: Thunder Wall gets +1/+1 until end of turn.

Phantasmal Mount

Flying
: Target creature you control with toughness 2 or less gets +1/+1 and gains flying until end of turn. When Phantasmal Mount leaves the battlefield this turn, sacrifice that creature. When the creature leaves the battlefield this turn, sacrifice Phantasmal Mount.

Sibilant Spirit

Flying
Whenever Sibilant Spirit attacks, defending player may draw a card.

Illusionary Forces

Flying
Cumulative upkeep (At the beginning of your upkeep, put an age counter on this permanent, then sacrifice it unless you pay its upkeep cost for each age counter on it.)

Osai Vultures

Flying
At the beginning of each end step, if a creature died this turn, put a carrion counter on Osai Vultures.
Remove two carrion counters from Osai Vultures: Osai Vultures gets +1/+1 until end of turn.

Mesa Pegasus

Flying; banding (Any creatures with banding, and up to one without, can attack in a band. Bands are blocked as a group. If any creatures with banding you control are blocking or being blocked by a creature, you divide that creature’s combat damage, not its controller, among any of the creatures it’s being blocked by or is blocking.)

Dragon Whelp

Flying
: Dragon Whelp gets +1/+0 until end of turn. If this ability has been activated four or more times this turn, sacrifice Dragon Whelp at the beginning of the next end step.

Killer Bees

Flying
: Killer Bees gets +1/+1 until end of turn.

Clockwork Avian

Flying
Clockwork Avian enters with four +1/+0 counters on it.
At end of combat, if Clockwork Avian attacked or blocked this combat, remove a +1/+0 counter from it.
, : Put up to X +1/+0 counters on Clockwork Avian. This ability can’t cause the total number of +1/+0 counters on Clockwork Avian to be greater than four. Activate only during your upkeep.

Serra Angel

Flying
Vigilance (Attacking doesn’t cause this creature to tap.)

Sengir Vampire

Flying (This creature can’t be blocked except by creatures with flying or reach.)
Whenever a creature dealt damage by Sengir Vampire this turn dies, put a +1/+1 counter on Sengir Vampire.