msem-instigator

{T}: Mystical Elk becomes a copy of target creature card in your graveyard. Activate only as a sorcery. (It loses this ability.)

When Nitrous Renewer enters, you may put a land card from your hand onto the battlefield tapped.
{3}{G}, Exile Nitrous Renewer from your graveyard: Return target land card from your graveyard to your hand. Activate only as a sorcery.

Kicker—Sacrifice an artifact or creature. (You may sacrifice an artifact or creature in addition to any other costs as you cast this spell.)
Choose target creature you control. Put a +1/+1 counter on it if this spell was kicked. Then it deals damage equal to its power to target creature you don't control.

Flash
Voracious 2 (As this enters, you may sacrifice up to two artifacts and/or creatures. This creature enters with that many +1/+1 counters on it.)

{1}: Exile target card from a graveyard.
At the beginning of combat on your turn, if there are three or more card types among cards exiled with Respectful Tracker, put a +1/+1 counter on target creature you control.

Destroy up to one target artifact, enchantment, or creature with flying. Create two 1/1 green Saproling creature tokens.

Flash
Enchant creature
When Roar of the Wilds enters, enchanted creature gets +3/+3 until end of turn.
When enchanted creature dies, create a 1/1 green Saproling creature token.

When Rotting Greatwurm dies, put three +1/+1 counters on target creature you control.
Fleeting {2}{G} (You may cast this spell for its fleeting cost. If you do, sacrifice it at the beginning of the next end step.)

Ruins Pack gets +2/+2 as long as you sacrificed a permanent this turn.

Create a 1/1 green Squirrel creature token.
The next creature spell you cast this turn can be cast as though it had flash. As you cast that spell, it gains voracious 2. (As it enters, you may sacrifice up to two artifacts and/or creatures. That creature enters with that many +1/+1 counters on it.)

Voracious 2 (As this enters, you may sacrifice up to two artifacts and/or creatures. This creature enters with that many +1/+1 counters on it.)
Each creature you control with a +1/+1 counter on it has trample.

Voracious 2 (As this enters, you may sacrifice up to two artifacts and/or creatures. This creature enters with that many +1/+1 counters on it.)

When Tumultuous Shrine enters or is put into a graveyard from the battlefield, up to one target land you control becomes a 4/4 Elemental creature with haste. It's still a land.

Search your library for up to four basic land cards, reveal them, put them into your hand, then shuffle. You may play an additional land this turn.

You may exert Wiedfree Behemoth as it attacks. When you do, it gets +3/+3 and gains trample until end of turn. (An exerted creature won't untap during your next untap step.)

Voracious 1 (As this enters, you may sacrifice an artifact or creature. If you do, it enters with a +1/+1 counter on it.)
Vigilance, reach

When Army Guide dies, you may search your library for a basic land card, put it onto the battlefield tapped, then shuffle.
{2}{G}{W}, Sacrifice Army Guide: Exile target noncreature, nonland permanent. Activate only as a sorcery.

Whenever one or more creatures you control deals combat damage to a player, you may sacrifice one of them. When you do, destroy target creature defending player controls, then you and the destroyed creature's controller draw a card.

Exile the top two cards of your library. Until your next end step, you may play those cards.
Whenever you cast your third spell each turn, you may exile Devoted Artistry from your graveyard. If you do, you may cast a copy of it at the beginning of your next upkeep. (You still pay its costs.)

Trample
{1}{G}{W}, Discard Enduring Force: Search your library for up to two basic land cards, reveal them, put them into your hand, then shuffle.
{G}{W}: Return Enduring Force from your graveyard to your hand. Activate only as a sorcery.

When Forlorned Knight enters, you may sacrifice another creature. If you do, create two 1/1 white Human creature tokens.
Whenever you attack, if another creature died under your control this turn, creatures you control get +1/+1 until end of turn.
Fleeting {W}{B} (You may cast this spell for its fleeting cost. If you do, sacrifice it at the beginning of the next end step.)

Creatures you control have deathtouch as long as they're attacking.
[+1]: Target creature you control must be blocked this turn if able.
[–2]: Create two 1/1 white Human creature tokens.
[–X]: Destroy target artifact or enchantment with mana value X and all other permanents with the same name as that permanent.

Flying
When Hallowed Perspective enters, investigate. (Create a colorless Clue artifact token with “{2}, Sacrifice this artifact: Draw a card.”)
You may exert Hallowed Perspective as it attacks. When you do, until your next turn, you may cast spells as though they had flash. (An exerted creature won't untap during your next untap step.)

You may exert Heavenly Bull as it attacks. When you do, it gains indestructible until end of turn. (An exerted creature won't untap during your next untap step.)
{3}{G}{W}: Destroy all nonland permanents with mana value 3 or less. Activate only if Heavenly Bull is attacking and only once.

{B}{R}, {T}, Sacrifice Heretical Soulshifter: Return target creature card from your graveyard to the battlefield. It gains haste until end of turn. Activate only as a sorcery.