msem-instigator

Menace (This creature can't be blocked except by two or more creatures.)
When Spawn of Shadows enters, each player loses 4 life.

Escalate {1}{W} (Pay this cost for each mode chosen beyond the first.)
Choose one or both —
• Return up to two target creature cards from your graveyard to your hand.
• Abound, abound. (To abound, you may cast a spell that costs less than this from your hand without paying its mana cost.)

You gain 3 life.
Amass Soldiers 1. (Put a +1/+1 counter on an Army you control. It's also a Soldier. If you don't control one, create an 0/0 black Soldier Army creature token first.)

Search your library for a land card, put it onto the battlefield tapped, then shuffle.
Spell mastery — If there are two or more instant and/or sorcery cards in your graveyard, untap that land.

Exile two target artifacts, creatures, and/or lands you control, then return those cards to the battlefield under your control.

Slipstream (This creature can't be blocked as long as only creatures with slipstream are attacking.)
Whenever Conchhorn Shinygrabber attacks, you may pay {1}. If you do, create a Treasure token. (It's an artifact with “{T}, Sacrifice this artifact: Add one mana of any color.”)
{W}{U}{B}{R}{G}: Conchhorn Shinygrabber gets +3/+3 and gains lifelink until end of turn.

Target creature gets +2/+0 and gains haste until end of turn.
Flashback {1}{R} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Golden age (If you cast an instant or sorcery spell, activated a nonmana ability, and attacked this turn, enter a renaissance for this game.)
{3}{G}: Harmonic Recruit gets +2/+2 until end of turn. If you're in a renaissance, it gets +4/+4 until end of turn instead.

Whenever Vanguard of the Barricade attacks, tap up to one target creature defending player controls and untap up to one other target creature you control.

Target creature gets +2/-2 and gains first strike until end of turn.

Codex — Aspiring Dragon; Scrappy Hatchling; Skiviar Scraplord; Blizzard Dragon; Cloud Swine; Gold Retriever; Ilieth, Transcendent. (As this enters, conjure its contents into a shuffled face-up additional library.)
At the beginning of your upkeep, you may put a card from this codex's library on the bottom of that library.

Exile target artifact, enchantment, or tapped creature.

At the beginning of your end step, draw a card for each card you drew this turn.

Enchant land you control
When Kelp Garden enters, mill three cards.
Whenever enchanted land is tapped for mana, add one mana of any color among cards in your graveyard.

Mill two cards, then you may return an instant or sorcery card from your graveyard to your hand.
Acquiesce (If you cast this spell from your hand, exile it as it resolves. When one or more creatures you control deal combat damage to an opponent, you may cast this card from exile without paying its mana cost.)

Look at the top two cards of your library. Put one of them into your hand and the other on the bottom of your library.

Flash
Reach
Glimmerbark Treant enters with X +1/+1 counters on it.
When Glimmerbark Treant leaves the battlefield, you gain life equal to its power.

This spell can't be countered.
Players can't gain life.
{1}{R}: This enchantment becomes a 4/4 red Elemental creature with trample and haste until end of turn. Activate only during your turn.

Target creature you control gains indestructible until end of turn if it's embattled. Then it fights target creature you don't control. (A creature is embattled if it has a counter on it or has a permanent you control attached to it.)

Return target nonland permanent to its owner's hand. If you control an Elemental, draw a card.

{U}: Pilgrim's Muse can't be blocked this turn.
{1}{U}: Return Pilgrim's Muse to its owner's hand.
{2}{U}: Scry 2.
{3}{U}: Draw a card.

When Destiny Beyond Measure enters, tap each creature you control.
Creatures you control get +8/+8 and have “This creature enters tapped.”

Reveal the top card of your library and put that card into your hand. If it's a permanent card with mana value X or less, instead you may put it onto the battlefield. If you do and fewer than seven permanents have been put onto the battlefield this way, repeat this process. X can't be 0.

When Saddled Scuttleback enters, you may search your library for a Crab, Fish, Jellyfish, Kraken, Leviathan, Merfolk, Nautilus, Octopus, Otter, Oyster, Pirate, Seal, Serpent, Shark, Shrimp, Sponge, Squid, Starfish, Trilobite, Turtle, Whale, or Island card, reveal it, put it into your hand, then shuffle.

Return target creature card from your graveyard to your hand. Add {G}{G}{G}. Spend this mana only to cast creature spells.