msem-instigator

Target player mills X cards, where X is the number of cards in your graveyard.
Flashback {3}{U/B}{U/B} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Destroy target nonbasic land.
Abound. (To abound, you may cast a spell that costs less than this from your hand without paying its mana cost.)

You may play an additional land on each of your turns.
Whenever Antali Archdruid attacks, if two or more lands you control entered this turn, Antali Archdruid deals 3 damage to any target and you gain 3 life.

Flying
When Cadre Hawk enters, you may search your library and/or graveyard for a card named Cadre Hawk, reveal it, and put it into your hand. If you searched a library this way, shuffle.

Target opponent chooses a card type, then reveals their hand. You choose a card from it that's not of the chosen type. That player discards that card.

Enchant creature
You control enchanted creature.
Enchanted creature gets +1/+1 and has slipstream. (This creature can't be blocked as long as only creatures with slipstream are attacking.)

Whenever you cast an instant or sorcery spell, create a 1/1 red Alien creature token with “This creature can't block.”
{2}{R}, Sacrifice two Aliens: Copy target instant or sorcery spell you control. You may choose new targets for the copy.

Flash
If a spell or ability an opponent controls would cause you to discard a creature card, you may put that card onto the battlefield instead.

(As you complete a condition, decode it. After all are decoded, you solve the mystery and transform this.)
When Mystery of the Crashed Craft enters, create two 1/1 red Alien creature tokens with “This creature can't block.”
{MG}—You cast an instant spell.
{MG}—You cast a sorcery spell.

Counter target instant or sorcery spell unless its controller pays {3}.

Flash
TT-23 Aegis can't attack or block unless you have six or more cards in hand.
At the beginning of your end step, if you didn't cast a spell this turn, draw a card.

Constructs you control have haste.
When Urak, Voice of the Horde or another Construct you control enters, creatures you control get +1/+0 until end of turn.
Respawn (When this creature dies, if it attacked this turn, return it to its owner's hand.)