msem-instigator

As an additional cost to cast this spell, sacrifice a creature.
Search your library for a creature card that shares a creature type with the sacrificed creature with mana value less than or equal to X plus the sacrificed creature's mana value, put it onto the battlefield, then shuffle.

Mill four cards, then return a creature or enchantment card from your graveyard to you hand. You gain 3 life.

Serpentine Woods enters tapped.
{T}: Add {B} or {G}.
{2}{B}{G}, {T}, Sacrifice Serpentine Woods: Draw a card.

Chronicle (As this enters and after your draw step, add a lore counter. Stop after III.)
[Lore I-II] Mill two cards.
[Lore III] Return target creature card from your graveyard to your hand.

Equipped creature gets +2/+2 and has ward {2} and “Whenever this creature attacks, draw a card, then you may put a land card from your hand onto the battlefield.”
Equip {2}

Heroic — Whenever you cast a spell that targets Setessan Avenger, create a 1/1 green Nymph Dryad enchantment creature token with “{T}: Add {G}.”
Whenever Setessan Avenger deals combat damage to a player, untap all lands and Dryads you control.

Sheltered Haven enters tapped.
{T}: Add {G} or {W}.
{2}{G}{W}, {T}, Sacrifice Sheltered Haven: Draw a card.

Whenever you scry, put a +1/+1 counter on Shimmershell.

Flying, vigilance

Put a +1/+1 counter on target creature. It gains hexproof until end of turn.

When Skittering Atrocity enters, up to one target creature gets -X/-X until end of turn, where X is the number of Horrors you control.

When Slyten Analyst enters, you may search your library for a card, then shuffle and put that card on top. If you do, you lose 2 life.

Whenever Slyten Connoisseur attacks, crystallize. (Put a +1/+1 counter on a creature you control or create a Treasure.)
Once each turn, when an artifact you control dies, you may pay 1 life. If you do, draw a card.

Whenever Slyten Jewel Runner attacks, target creature can't block until end of turn.
Augmented — At the beginning of your end step, if you've spent {W}{U}{B}{R}{G} to cast spells this turn, put a +1/+1 counter on Slyten Jewel Runner.

Look at the top three cards of your library. Put one of them into your hand and the rest into your graveyard.
Augmented — If you've spent {W}{U}{B}{R}{G} to cast spells this turn, put two of those cards into your hand instead.

As an additional cost to cast this spell, discard a card.
Draw two cards and crystallize twice. (Put a +1/+1 counter on a creature you control or create a Treasure. Then do it again.)

Reveal the top five cards of your library. You may put a permanent card revealed this way into your hand and the rest into your graveyard.

Solar Pulse deals 3 damage to target attacking or blocking creature.

Enchant permanent
Enchanted permanent is a land with “{T}: Add {G}{W}{U}” and loses all other card types and abilities.
{1}, Discard Song of Shoals: Add one mana of any color. Scry 1.

Spend only black mana on X.
Any number of target players each draw X cards and lose X life.

Flying
When Spawn of Keranos enters, you may draw a card. If you do, discard a card unless you control another creature with flying.

Whenever you cast a noncreature spell, create a 1/1 colorless Servo artifact creature token.
{1}{U}, {T}, Exile three noncreature cards from your graveyard: Draw a card.

Haste
Ward—Sacrifice a creature.
Spinning Gears Abomination enters with X +1/+1 counters on it.
Spinning Gears Abomination can't attack alone.

For each creature you control, put a +1/+1 counter on it or create a Treasure token.

Chronicle (As this enters and after your draw step, add a lore counter. Stop after III.)
[Lore I-II] Another target creature you control gets +1/+1 until end of turn.
[Lore III] Search your library for a basic land card, put it onto the battlefield, then shuffle.