msem-instigator

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.

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.

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

Lifelink
When Seeker of Lost Secrets leaves the battlefield, you may pay 2 life. If you do, search your library for a card, put that card into your hand, then shuffle.

As long as you control four or more lands, Seeker of Untouched Beauty gets +2/+2 and has trample.
When Seeker of Untouched Beauty dies, you may search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

Create a 1/1 colorless Construct artifact creature token. If you control an artifact, create two of those tokens instead.

[+1]: You may sacrifice a permanent. If you do, each opponent sacrifices a permanent that shares a type with it.
[–2]: Put target creature card in a graveyard onto the battlefield under your control.
[–8]: You control target player during their next turn. During that turn, that player may cast spells by paying life equal to their mana value rather than pay their mana cost. After that turn, that player takes an extra turn.

Shadowcleft Hideout enters tapped.
{T}: Add {B}.
{T}, Pay 2 life, Sacrifice Shadowcleft Hideout: Draw a card.

As long as Shambling Morass is on the battlefield or in your graveyard, it's a land in addition to its other types.
When Shambling Morass dies, you may pay {1}. If you do, you draw a card and you lose 1 life.

Discard a land card: Draw a card. Shardstorm Elemental gets +1/+0 and gains flying until end of turn. Activate only once each turn.

Wanderlust — Return target nonland permanent to its owner's hand. If you control four or more differently named lands, you may aetherize that permanent. (To aetherize, create a token that's a copy of it, then exile that token.)

Flying
When Shiftscale Drake enters, look at the top card of your library. You may put that card into your graveyard.

{T}: Add {C}.
{T}, Sacrifice Shiftscape Canyon: Choose a basic land type other than Plains. Create a colorless land token that's a Plains and the chosen basic land type. Activate only during your upkeep.

{T}: Add {C}.
{T}, Sacrifice Shiftscape Cascade: Choose a basic land type other than Island. Create a colorless land token that's an Island and the chosen basic land type. Activate only during your upkeep.

{T}: Add {C}.
{T}, Sacrifice Shiftscape Crag: Choose a basic land type other than Mountain. Create a colorless land token that's a Mountain and the chosen basic land type. Activate only during your upkeep.

{T}: Add {C}.
{T}, Sacrifice Shiftscape Grove: Choose a basic land type other than Forest. Create a colorless land token that's a Forest and the chosen basic land type. Activate only during your upkeep.

{T}: Add {C}.
{T}, Sacrifice Shiftscape Morass: Choose a basic land type other than Swamp. Create a colorless land token that's a Swamp and the chosen basic land type. Activate only during your upkeep.

({T}: Add {B} or {G}.)
Shuddering Node enters tapped.
{1}, {T}: Add {B}{B} or {G}{G}.

Flying, vigilance
When Silksoul Celestial enters, search your library for an enchantment or Aurashaper card, reveal it, put it into your hand, then shuffle.
When Silksoul Celestial dies, you may put an enchantment or Aurashaper card from your hand or graveyard onto the battlefield.

When Silkweaver Matron enters, create a white Aura enchantment token named Spinning Silk attached to target creature. The token has enchant creature and “Whenever enchanted creature attacks, tap target creature defending player controls.”
{1}{W}: Untap target enchanted creature.

[+1]: Gain control of up to one target noncreature permanent you don't control until end of turn. Untap it.
[0]: Target player gains control of target permanent you control.
[–7]: You get an emblem with “Whenever you target one or more permanents, gain control of those permanents.”

Skylight Fortress enters tapped.
When Skylight Fortress enters, you may search your library for a card named Skylight Fortress, reveal it, put it into your hand, then shuffle.
{T}: Add {C}.

This spell costs {1}{B} less to cast if it targets a creature with indestructible.
Exile target creature.

{T}: Add {C}.
{T}: Add one mana of any color. You can't spend this to cast spells from your hand.

Flying
Whenever Soaring Biome attacks, create a Plains token, Island token, Swamp token, Mountain token, or Forest token. Sacrifice that land at the beginning of the next end step.
Crew 2 (Tap any number of creatures you control with total power 2 or greater: This Vehicle becomes an artifact creature until end of turn.)