msem-instigator

Search your library for a basic land card, reveal it, put it into your hand, then shuffle.(Cast a copy of this spell once while this creature is on the battlefield.)

“I was filled with fear, but looking across our great city, I know we will survive.”
I — Create a 0/4 white Wall creature token with defender.
II — Put a +1/+1 counter on up to one target creature.
III — Until your next turn, each creature you control assigns combat damage equal to its toughness rather than its power.

Take an extra turn after this one. During that extra turn, you may cast spells you own not named See the World from outside the game by tapping an untapped Scout you control in addition to paying their mana costs.
Exile See the World.

Breach (Whenever this deals combat damage to a player, you may have it become an Aura Curse until your next turn. Attach it to that player.)
Each cursed opponent must attack with at least one creature each combat if able.

Create three 0/1 green Plant creature tokens.

At the beginning of combat on each of your turns, you may have target land you control become a 3/3 Elemental creature with haste until end of turn. It's still a land.
Sacrifice Seeds of New Life: Return up to two target land cards from your graveyard to your hand. Activate only as a sorcery.

Shuffle up to five target cards from your graveyard into your library. Reveal the top five cards of your library. An opponent separates those cards into two piles. Put one pile into your hand and the other into your graveyard.

{T}, Pay 1 life: Add {B} or {G}.
{1}, {T}, Sacrifice Seedy Bar: Investigate. (Create a colorless Clue artifact token with “{2}, Sacrifice this artifact: Draw a card.”)

Draw three cards. Then discard two cards unless you discard a land card.

(Add a quest counter as this enters. Sacrifice after 3.)
Whenever a land you control enters, add a quest counter.
Create a 1/1 Scout creature token that's all colors.
Creatures you control get +2/+1 until end of turn.
Creatures you control get +1/+1 until end of turn.

Draw a card.
Whenever Seek Guidance is put into your graveyard from your hand or library, scry 2. (This doesn't include being cast.)

Prevent all damage that would be dealt to creatures and to you this turn.

Whenever you draw a card, put a quest counter on Seek Perfection.
At the beginning of each end step, if Seek Perfection has four or more quest counters on it, exile target permanent you control, then return it to the battlefield under your control.

Look at the top five cards of your library. You may reveal a creature card or a land card from among them and put it into your hand. Put the rest into your graveyard.
Abound. (To abound, you may cast a spell that costs less than this from your hand without paying its mana cost.)

At the beginning of your upkeep, you gain 1 life. Then if your life total is greater than or equal to your starting life total, you gain an additional 1 life and scry 1. Then if your life total is greater than or equal to three times your starting life total, you win the game.

(Add a quest counter as this enters. Sacrifice after 3.)
Whenever a creature you control enters, add a quest counter.
You gain 3 life.
Search your library for an Equipment card, reveal it, and put it into your hand. Then shuffle.
You may put an Equipment card from your hand onto the battlefield and attach it to a creature you control.

Scry 2, then draw two cards.
You have no maximum hand size for the rest of the game.

(Add a quest counter as this enters. Sacrifice after 3.)
Whenever you attack, add a quest counter.
Create a 0/1 white Human creature token named Lost Child.
Scry 2.
Exile a token you control named Lost Child. If you do, create two 1/1 white Soldier creature tokens and you gain 4 life.

(Add a quest counter as this enters. Sacrifice after 3.)
Whenever another artifact or enchantment you control enters, add a quest counter.
You gain 3 life.
Mill three cards, then return an artifact or enchantment card from your graveyard to the battlefield. Exile Seek the Maker's Egg.
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Flash
Flying
When Seeker Amalgam enters, you may counter target spell with mana value less than or equal to the number of Elementals you control.

Whenever you play a land, investigate. (Create a colorless Clue artifact token with “{2}, Sacrifice this artifact: Draw a card.”)
{1}{G}{U}{R}, Sacrifice three Clues: Exile cards from the top of your library until you exile three nonland cards. You may cast any number of those cards without paying their mana costs.

{T}: Add {R} or {W}.
{R}{W}, {T}: Target creature gains first strike and haste until end of turn.

As long as a creature you control has flying, creatures you control have flying. The same is true for first strike, double strike, deathtouch, haste, hexproof, indestructible, lifelink, menace, reach, trample, and vigilance.

Whenever Seeker of Battle attacks, put a +1/+1 counter on each creature you control. Those creatures gain trample until end of turn.

When Seeker of Communions enters, choose target player. If that player is poisoned, draw a card. Otherwise, that player gets a poison counter.