msem-instigator

Ward {2} (Whenever this creature becomes the target of a spell or ability an opponent controls, counter it unless that player pays {2}.)
{2}{W}{W}, Return an unblocked attacking creature you control to its owner's hand: Create a 4/4 white Angel creature token with flying that's tapped and attacking.

For each player, you choose from among the permanents that player controls an artifact, a creature, an enchantment, and a planeswalker. Then each player sacrifices all other nonland permanents they control.

Whenever a nonland permanent enters under an opponent's control this turn, gain control of that permanent until the end of your next turn. It gains haste until end of turn.

At the beginning of your end step, choose any number of permanents and/or players, then give each another counter of each kind it already has.
[+1]: Scry 1. Add {U} or {R}.
[–X]: Exile the top X cards of your library. Until end of turn, you may play a card exiled with Trainee Karina Oblay.

Each creature you control enters with an additional +1/+1 counter on it.
When Training Sim enters, create a Function token with “Target creature you control fights target creature you don't control.” (It's an enchantment. As you cast an instant or sorcery spell, sacrifice any number of Functions to add their effects to that spell.)

Equipped creature gets +2/+2 and has hexproof and vigilance.
Equip {2}

When you cast this spell, copy it for each player that has 8 or less life. (The copies have the same target.)
Traitor's Execution deals 3 damage to target player.

Choose one —
• Each player skips their next combat step.
• Each opponent can't cast instant or sorcery spells this turn.

Prevent all combat damage that would be dealt this turn.
Draw a card.

{4}{W}{W}: Create a 4/4 white Angel creature token with flying.
{2}{W}{W}: Populate. (Create a token that's a copy of a creature token you control.)

You may exile a land card from your hand rather than pay this spell's mana cost.

{T}: Add {C}.
{7}: Transplanted Citadel becomes a 6/6 Golem artifact creature until end of turn. It's still a land. This ability costs {1} less to activate for each artifact you control.

You may reveal creature cards with mana value 3 or less as you draw them. Once each turn, when you reveal a card this way, you may aetherize it. (To aetherize, create a token that's a copy of it, then exile that token.)

Create two 1/1 red Elemental creature tokens.
Spell mastery — If there are two or more instant and/or sorcery cards in your graveyard, you may change the targets of up to one target spell or ability.

When Trapped in the Tower enters, exile target creature an opponent controls until Trapped in the Tower leaves the battlefield. (That creature returns under its owner's control.)
When you lose life, sacrifice Trapped in the Tower.

Choose a nonland card name. Search target player's graveyard, hand, and library for any number of cards with that name and exile them. That player shuffles. For each card exiled from their hand this way, you discard a card.

Creatures you control have “When this creature becomes tapped for the first time during each of your turns, untap it.”
{T}: Add one mana of any color.

When Traversing Bulkvine enters, search your library for three land cards with different names and reveal them. An opponent chooses one of them. Put that card into your graveyard and the rest into your hand, then shuffle.

Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)
Whenever you cast your first instant or sorcery spell each turn, copy that spell. You may choose new targets for the copies.

For each permanent type, return up to one target card of that type from your graveyard to your hand. (The permanent types are artifact, creature, enchantment, land, and planeswalker.)

Choose one —
• Return target creature to its owner's hand unless that player pays {1}.
• Counter target noncreature spell unless its controller pays {1}.

Bleed {1}{B} (You may cast this spell for its bleed cost if an opponent lost life this turn.)
Deathtouch
Treacherous Informant enters with two +1/+1 counters on it if you paid its bleed cost.
You may cast spells for their bleed costs if you lost life this turn.

Treacherous Oasis enters tapped.
{T}: Add {U} or {B}.
{2}{U}{B}: Until end of turn, Treacherous Oasis becomes a Crocodile creature in addition to its other types. It can't be blocked this turn.
Scavenge {1}{U}{B}

When Treacherous Warden enters, search your library for a card, put into your graveyard, then shuffle.
Whenever a creature enters from your graveyard, each opponent loses 2 life and you gain 2 life.

(Add a quest counter as this enters. Sacrifice after 3.)
Whenever you scry or search your library, add a quest counter.
Target creature you don't control gets -3/-0 until your next turn.
Reveal cards from the top of your library until you reveal a nonland card, then put the revealed cards into your hand.
Reveal the top card of your library. If its mana value is less than or equal to the number of cards in your hand, you may cast it without paying its mana cost.