msem-instigator

{X}{G}: Put X +1/+1 counters on target noncreature, nonplaneswalker permanent you control. It becomes an Elemental creature with base power and toughness 0/0 in addition to its other types. (This effect lasts indefinitely.)

Codex — Out-of-Body Experience; Event Horizon; Strike from the Shadows; Second Death; Anguished Unmaking. (As this enters, conjure its contents into a shuffled face-up additional library.)
You can't draw from this codex's library.
Whenever a creature you control dies, put a card from this codex's library into your hand.

The Mythical Zhiwu enters with four +1/+1 counters on it.
{1}, Remove a +1/+1 counter from a creature you control: Target creature gets -1/-1 until end of turn. Activate only as a sorcery.
{1}, Remove a +1/+1 counter from a creature you control: Each opponent loses 1 life and you gain 1 life.

The Oltenen Emissary is all colors.
You may pay {W}{U}{B}{R}{G} rather than pay the mana cost for spells that you cast. When you do, you may cast spells without paying their mana costs until end of turn.

Indestructible
Spells you cast from your graveyard cost {6} less to cast.
Whenever you attack, you may cast any number of target cards from your graveyard this turn. If a spell or permanent that was cast this way would be put into a graveyard, exile it instead.

As an additional cost to cast this spell, you may tap any number of creatures you control. This spell costs {1} less to cast for each creature tapped in this way.
Create X 1/1 white Peasant creature tokens. You gain X life. Legendary creatures you control gain hexproof and indestructible until end of turn.

Equipped creature gets +2/+2 and has deathtouch and lifelink.
Whenever equipped creature dies, you may exile it. If you do, return target Knight or Soldier card from your graveyard to the battlefield tapped, then attach The Roseblade to it.
Equip {2}

Once each turn, when another permanent you control enters, you may create a token that's a copy of that permanent, except it has no mana cost.

Flash
{1}{W}: Exile target creature that dealt damage to you this turn until The Shield leaves the battlefield.

Flying
Spirited (When this creature enters, you may activate one of its activated abilities without paying its costs.)
Harmony — Draw three cards.
{2}{G}{G}: Harmonize. (Trigger up to one harmony of a permanent you control.)

Create a 1/1 white Spirit creature token with flying. (Then exile this card. You may cast the artifact later from exile.)

At the beginning of each player's end step, that player chooses from among nonland permanents they control an artifact, a creature, an enchantment, and a planeswalker, then sacrifices the rest.

For each legendary permanent you control, this spell costs one mana of one of that permanent's colors less to cast. This effect reduces only the amount of colored mana you pay.
For each color, create a token that's a copy of a different legendary permanent you control of that color, except the token isn't legendary.
Exile The Tale of Kings.

When The Third Breach enters, discard your hand, then draw seven cards.
Creatures you control get +3/+3, have haste, and are Horrors in addition to their other types.
At the beginning of each end step, sacrifice each creature you control.

Defender
Your maximum hand size is thirteen.
{T}: If you have fewer than thirteen cards in hand, draw cards equal to the difference. Activate only as a sorcery.

Whenever you sacrifice a Clue, you lose life equal to the number of Clues you control, then investigate twice. (Create a colorless Clue artifact token with “{2}, Sacrifice this artifact: Draw a card.”)

[0]: Creatures you control gain haste until end of turn. Whenever a creature attacks this turn, put a loyalty counter on The Warrior Within.
[–1]: Exile the bottom two cards of your library. You may play one of them this turn.
[–6]: Untap each creature that attacked this turn. After this main phase, there is an additional combat phase.

Whenever The Wicker Lord or another Scarecrow you control enters, create a 1/1 black Bird creature token with flying for each Scarecrow you control.
{4}, Sacrifice a Scarecrow: Return target artifact card from your graveyard to the battlefield.

[+2]: The Witch Queens deal 2 damage to each of up to two targets.
[–3]: Gain control of target land and untap it.
[–9]: Each player discards their hand, then draws up to seven cards. The Witch Queens deal damage to each opponent equal to twice the number of cards that player has drawn this turn.

Rhapsody {4}{U}{U} (Pay {4}{U}{U} to cast this as a 4/4, or as a sorcery to make it become a 4/4.)
Whenever you draw a card, any number of target players mill two cards.
Whenever This Is Not Our Fate deals combat damage to a player, for each player, you may cast an instant or sorcery card from that player's graveyard without paying its mana cost.

Primal {5}{R}{W} (During your turn, you may cast this spell for {5}{R}{W} instead of playing a land.)
Until end of turn, permanents you control gain indestructible and permanents you don't control lose indestructible. Then if if this spell was cast for its primal cost, destroy all nonland permanents.

At the beginning of each player's draw step, that player draws two additional cards. At the beginning of their next end step, they discard their hand.

Other creatures have haste and attack each combat if able.
Nonland cards in your hand have paranoia {4}. (The owner of a card with paranoia {4} may cast it from their hand for {4} when a permanent they control leaves the battlefield.)

Whenever you draw a card, you may have target opponent exile the top card of their library face down.
You may look at and play cards exiled with Thought Siphon, and you may spend blue mana as though it were mana of any color to cast them.

Reveal the cards in your library. Target opponent chooses three nonland cards with different names from it. You put the chosen cards into your hand. Then shuffle.