msem-instigator

When Broadside Raider enters, create a 1/1 blue and red Pirate creature token with haste.

Target creature gets +2/+2 and gains lifelink until end of turn. Whenever that creature perseveres this turn, target opponent loses 2 life. (A creature perseveres when it survives damage.)

When Biohazard enters, destroy all other nonland permanents with mana value X or less.
At the beginning of each end step, each opponent loses life equal to the number of cards they've drawn this turn plus the number of spells they've cast this turn.

Archive 4 (As this enters, shuffle the top four cards of your main library into a new face up library. Sacrifice this after the archived library is empty.)
{1}, Sacrifice a permanent: Put a permanent card with a mana value less than the sacrificed permanent's from the archived library onto the battlefield. Activate only as a sorcery.

Lifelink
Art of war — At the beginning of your end step, if Takaki's Kihei dealt damage to an opponent this turn, untap target creature you control.

Enchant creature
Enchanted creature gets +1/+1.
Sacrifice Bear Necessities: Enchanted creature gains indestructible until end of turn.

You may look at the top card of your library any time.
Once each turn, you may cast an instant or sorcery spell from the top of your library.
{4}{R}: Transform Paranormal Convergence. Activate only as a sorcery and only if the total number of instant and/or sorcery cards you own in exile and in your graveyard is seven or more.

As an additional cost to cast this spell, pay 3 life and sacrifice a creature.

Haste
When Inciter of Spirits Scorned enters, return target creature card with mana value 3 or less from your graveyard to the battlefield. It gains haste. Sacrifice it at the beginning of the next end step.

Ferocious — Once each turn, when a creature you control with power 4 or greater enters, you may untap all lands you control.

This spell costs {3} less to cast if it targets a creature with mana value 2 or less.
Destroy target creature.

Whenever Dunesea Dreadstalker or another nontoken creature you control dies, amass Soldiers 1. (Put a +1/+1 counter on an Army you control. It's also a Soldier. If you don't control one, create an 0/0 black Soldier Army creature token first.)

Concord — {T}, Sacrifice Disciple of Destruction: Destroy target nonland permanent. Activate only if there are four or more card types among permanents you control.

Whenever Soli Arbalist or a nontoken Angel or Nephilim you control enters, amass Soldiers 2. If it was an Angel, amass Soldiers 4 instead. (To amass Soldiers {2}, put two +1/+1 counters on an Army you control. It's also a Soldier. If you don't control one, create a 0/0 black Soldier Army creature token first.)

Menace
Whenever Diregraf Skulleater deals combat damage to a player, that player discards a card.
Whenever one or more cards leave your graveyard, put a +1/+1 counter on Diregraf Skulleater.

As long as an opponent has one or fewer cards in hand, Valdez gets +2/+0 and has menace.

Flying, menace, trample
When The Wickerscreech of Gatstaf dies, destroy target nonland permanent an opponent controls.
Foreshadow {13}. This costs {1} less for each nonland card in your graveyard. (You may cast this spell for its foreshadow cost. If you do, also trigger its “dies” abilities when it enters.)

Dunesea Expanse enters tapped unless you control another Desert.
{T}: Add {W} or {U}.

Target player shuffles up to three target cards from their graveyard into their library.
Acquiesce (If you cast this spell from your hand, exile it as it resolves. When one or more creatures you control deal combat damage to an opponent, you may cast this card from exile without paying its mana cost.)

When Cosmonaut Pioneer enters or leaves the battlefield, choose one—
• Scry 1, then draw a card.
• Create a 3/3 green Alien creature token with trample.
• You gain 5 life.

Target creature you control explores. Then it fights up to one target creature you don't control. If that creature has flying, the creature you control deals damage equal to its power to it instead. (Reveal the top card of your library. Put it into your hand if it's a land. Otherwise, put a +1/+1 counter on that creature, then you may put that card in your graveyard.)

Flying
Eyes of Cyrukan can't block.

Colossal 2—{3}{R} (You may cast this for its colossal cost to have it enter with two +1/+1 counters; or pay {3}{R} as a sorcery: Put two +1/+1 counters on it if it has none.)
When Emberhound's colossal ability puts one or more counters on it, target creature can't block this turn.

{1}{W}: Target creature you control gets +0/+1 until end of turn and assigns combat damage equal to its toughness rather than its power this turn. When that creature deals combat damage to a player this turn, transform Reversal Medic.

Creatures you control get +2/+1 until end of turn. Scry 1.