msem-instigator

As long as Sigiled Scrollcase is attached to a creature you control, you have no maximum hand size.
Whenever equipped creature dies, draw a card.
Equip {1}

When Horizon Treader enters, you may exile target enchantment you control. Return that card to the battlefield under your control at the beginning of the next end step.

Other Warriors you control have trample.
{G}: Chratteri Valiant gets +2/+2 and gains trample until end of turn. Activate only once each turn.

Citadel Bagworm gets +0/+1 for each card in your graveyard.
{B}, Discard a card: Switch Citadel Bagworm's power and toughness until end of turn.

Proliferate (Choose any number of permanents and/or players with counters on them, then give each another counter of each kind already there.)
Scry 2, then draw a card.

Foretell {2}{U} (During your turn, you may pay {2} and exile this card from your hand face down. Cast it on a later turn for its foretell cost.)
If this spell is foretold, you may cast it as though it had flash.
Create a token that's a copy of target creature you control.

{1}{B}: Target Knight or Soldier you control gains deathtouch until end of turn.

Haste
At the beginning of your end step, return Preying Mantis to its owner's hand.

Target creature gains hexproof and trample until end of turn. If Thunderous Charge was cast from exile, that creature gets an additional +4/+4 until end of turn.
Orchestrate {G}{G} (You may exile this card from your hand anytime you could cast a sorcery for its orchestrate cost. When you next resolve a spell, you may cast this from exile without paying its mana cost.)

Target player discards two cards.
Coalesce {8}{B} (You may cast this from your graveyard for {8}{B}. If you do, it enters as a Horror creature after it resolves. Exile it if it would leave the battlefield or not resolve.)

Other Spirits you control get +1/+1.
Whenever Mistmourner or another Spirit you control enters, you may draw a card. If you do, discard a card.

Whenever a +1/+1 counter is put on a creature you control, scry 1.
Each creature you control with a +1/+1 counter on it has lifelink.

Forgotten Attic enters tapped.
When Forgotten Attic enters, look at the top card of your library. You may put it into your graveyard.
{T}: Add {U} or {B}.

Equipped creature has lifelink as long as it's white. The same is true for flying and blue, menace and black, first strike and red, and trample and green.
Equip {1}

Add {W}{U}{B}{R}{G}. Spend this mana only to cast spells from your graveyard or activate abilities of cards in your graveyard.

Flying
When Sigarda's Shepherd enters, another target creature you control gets +1/+1 and gains indestructible until end of turn.

Flying
Mind's Contagion has haste as long as there are two or more creature cards in your graveyard.
Whenever Mind's Contagion deals combat damage to a player, until your next turn, it gains “Noncreature spells opponents cast cost an additional 2 life to cast.”

{1}, Sacrifice Zhedina Confiscator: Destroy target artifact or enchantment.

{1}{G}: Purge. If you do, put a +1/+1 counter on Purging Watchwarden and you gain 2 life. (To purge, exile two cards that share a type from graveyards. If you do, draw a card.)

{3}{W}{W}: Detain target nonland permanent. (Until your next turn, that permanent can't attack or block and its activated abilities can't be activated.)

Spells can't be cast from libraries.
If a nonland permanent would enter from a library, exile it instead.

Double strike
Distorted (This creature can be blocked by tapped creatures but not untapped creatures.)
Engage (This creature must be blocked each combat if able.)

Trample
When Rundfora Communionist enters, return a creature you control to its owner's hand.
Creature spells you cast cost {1} less to cast.

If a permanent with spirited entering the battlefield causes a triggered ability of a permanent you control to trigger, that ability triggers an additional time.