Trample (This creature can deal excess combat damage to the player or planeswalker it's attacking.)
Haste (This creature can attack and as soon as it comes under your control.)
At the beginning of the end step, sacrifice this creature.

When Balduvian Horde enters, sacrifice it unless you discard a card at random.

Flying
Sacrifice a creature: Fallen Angel gets +2/+1 until end of turn.

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.

Flying (This creature can't be blocked except by creatures with flying or reach.)

Trample (This creature can deal excess combat damage to the player or planeswalker it's attacking.)
At the beginning of your upkeep, Force of Nature deals 8 damage to you unless you pay .

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

Flying
: This creature gets +1/+0 until end of turn.

Flying
: Untap Blizzard Elemental.

Trample
Leviathan enters tapped and doesn't untap during your untap step.
At the beginning of your upkeep, you may sacrifice two Islands. If you do, untap Leviathan.
Leviathan can't attack unless you sacrifice two Islands. (This cost is paid as attackers are declared.)