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.)

At the beginning of combat on your turn, up to one target artifact you control becomes a creature in addition to its other types and gains “This creature's power and toughness are each equal to the number of artifacts you control” and “{U}: Exile this creature, then return it to the battlefield under your control.”

{T}, Sacrifice Adaptive Terrains: Search your library for a basic land card and put it onto the battlefield tapped, then shuffle.

Ward {2} (Whenever this creature becomes the target of a spell or ability an opponent controls, counter it unless that player pays {2}.)
Heroic — Whenever you cast a spell that targets Aegis Hero, put a +1/+1 counter on Aegis Hero.

Haste
Heroic — Whenever you cast a spell that targets Akroan Siege Captain, put a +1/+1 counter on each creature you control.

Akroan Truespear has first strike as long as it's attacking.
Heroic — Whenever you cast a spell that targets Akroan Truespear, put a +1/+1 counter on Akroan Truespear.

Search your library for a basic land card, put it onto the battlefield, then shuffle.
Crystallize. (Put a +1/+1 counter on a creature you control or create a Treasure.)

Whenever Align with Animus Vox enters or you attack with three or more creatures, crystallize. (Put a +1/+1 counter on a creature you control or create a Treasure.)

Destroy up to X target artifacts and/or enchantments. If X is 3 or more, you gain twice X life. If X is 6 or more, create two X/X Elemental creature tokens that are all colors.

Enchant creature
Enchanted creature doesn't untap during its controller's untap step.
Enchanted creature loses all abilities except for mana abilities.

Trample
Each creature you control with a counter on it has trample.

Reach
When Ambush Predator enters, you may return target Horror creature card from your graveyard to your hand.
When Ambush Predator dies, exile it and create a 3/2 green Horror creature token.

Create two 1/1 blue Elemental creature tokens with flying.
Reconstruct {7}{U} (You may cast this from your graveyard for its reconstruct cost reduced by the mana value of a permanent you sacrifice as you cast it this way. Then exile this.)

Whenever Ancient Durumderm attacks, you may return another creature you control to its owner's hand. If you do, create a Treasure token. (It's an artifact with “{T}, Sacrifice this artifact: Add one mana of any color.”)

Target creature gains indestructible until end of turn. Untap it.
Draw a card.

Flash
Rhapsody {5}{U}{U} (Pay {5}{U}{U} to cast this as a 4/4, or once it is in play to make it become a 4/4.)
Animus Channeler's rhapsody cost can be paid any time you could cast an instant.

Flash
You may cast Elemental spells as though they had flash.
Once each turn, when you cast an instant spell, you may put a +1/+1 counter on target Elemental you control.

Flying, vigilance
Augmented — When Antigravity Agent enters, if you've spent {W}{U}{R}{B}{G} to cast spells this turn, distribute a flying counter and a vigilance counter among one or two creatures you control.

Colossal 4—{8} (You may cast this for its colossal cost to have it enter with four +1/+1 counters; or pay {8} as a sorcery: Put four +1/+1 counters on it if it has none.)
Abilities you activate that aren't mana abilities cost {2} less to activate. This effect can't reduce the mana in that cost to less than one mana.

Flash
Flying

Vigilance, trample
Whenever another Horror you control enters, choose one —
• Destroy target artifact or enchantment.
• You gain 4 life.
• Apex Abomination fights another target creature.

Wanderlust — When you cast this spell, you may copy it if you control four or more differently named lands.
Exile the top card of your library. Until the end of your next turn, you may play that card. Create a 1/1 Scout creature token that's all colors.

Flying, lifelink
{2}{W}{W}, Exile Archon of Sunrise from your graveyard: Create a token that's a copy of it, except it's an Aura enchantment with enchant creature and “Enchanted creature gets +4/+4 and has flying and lifelink.” Activate only as a sorcery.

Whenever you cast a noncreature spell, each opponent loses 1 life.
{4}, Exile Arisen Psion from your graveyard: Draw a card.

As an additional cost to cast this spell, you may sacrifice three artifacts.
Search your library for an artifact card, reveal it, put it into your hand, then shuffle. If you sacrificed three artifacts as you cast this spell, you may put a noncreature artifact card from your hand onto the battlefield.