msem-instigator

When Relentless Pathcutter enters, create a green Aura enchantment token named Enmity attached to target creature. The token has enchant creature and “Enchanted creature gets +2/+0 and has trample.”
When Relentless Pathcutter dies, return it to its owner's hand.

[+1]: Untap up to one target creature. It gains deathtouch until your next turn.
[–2]: Target player sacrifices a creature. Return a permanent card from your graveyard to your hand.
[–5]: Put any number of permanent cards from your graveyard onto the battlefield, then sacrifice that many permanents.

{T}: Add one mana of any color.

When The Raven Queen of Fretport enters, put a -1/-1 counter on each of any number of target creatures.
{2}{U}{B}: Proliferate. (Choose any number of permanents and/or players with counters on them, then give each another counter of each kind already there.)

Persist (When this creature dies, if it had no -1/-1 counters on it, return it to the battlefield under its owner's control with a -1/-1 counter on it.)

Whenever you cast a cryptic spell, Oasis Cattle gets +1/+1 until end of turn, then untap it. (Artifacts, enchantments, and modal spells are cryptic.)

Whenever an Equipment you control enters, attach it to target creature you control.

Trample

Instant and sorcery spells you cast cost {1} less to cast.
Reprise and reverberate costs you activate cost up to {1} less.
Exile an instant or sorcery card from your graveyard: Add {U} or {R}. Spend this mana only to cast an instant or sorcery spell. Activate only once each turn.

Discard your hand, then for each creature you control that dealt combat damage to a player this turn, draw a card and create a Treasure token.
{1}{R}, Tap an untapped Pirate you control, Discard Pieces of Eight: Create a 2/1 black and red Cat Pirate creature token with menace.

Thriving Isle enters tapped.
As Thriving Isle enters, choose a color other than blue.
{T}: Add {U} or one mana of the chosen color.

As an additional cost to cast this spell, return any number of creatures you control to their owner's hands. This spell costs {1} less to cast for each creature returned this way.
Whenever Gwynsivir attacks, if a creature entering causes a triggered ability of a permanent you control to trigger this turn, that ability triggers an additional time.

Whenever a storied permanent you control enters, you gain 1 life and each opponent loses 1 life. (Enchantments and legendary permanents are storied.)

(Add a quest counter as this enters. Sacrifice after 3.)
Once each turn, when you cast a creature spell, you may add a quest counter.
1, 2 — Return up to X target creatures you control to their owner's hand, where X is the number of quest counters on Paw Valley Expedition.
3 — Create a 1/2 white Bear Monk creature token with vigilance and a 2/1 white Bear Knight creature token with first strike.

Search target opponent's library for a card with mana value 3 or less and exile it with a smoke counter on it. Then that player shuffles. You may play that card for as long as it remains exiled, and you may spend mana as if it were any color to cast it.

Equipped creature gets +6/+6.
If equipped creature would deal combat damage to a creature or planeswalker, instead gain control of that permanent for as long as you control Glorious Plate.
Equip {6}

Target attacking creature gets +1/+0 until end of turn. When that creature dies this turn, it deals damage equal to its power to defending player.

Gestalt (When this or another creature you control enters, you may merge it with the one in play, keeping counters and attachments. They become the permanent on top plus all abilities from under it.)
This permanent gets +2/+2 for each card and token merged with it.

Untap up to two target lands you control. Those lands become the basic land type of your choice until end of turn.
Draw a card.

Create a Treasure token.
Showcase {2}{R} (Then if you cast this for its showcase cost, create a 1/1 red Bard creature token that can't block and exile this. Whenever it attacks, you may cast a free copy of this.)

Destroy all creatures, then return all nonland permanents to their owner's hands.

Destroy target creature. Investigate. (Create a colorless Clue artifact token with “{2}, Sacrifice this artifact: Draw a card.”)

Choose one —
• Draw two cards, then discard a card.
• Counter target spell unless its controller pays {3}.

Exile target attacking or blocking creature with power 4 or less.

Trample
When Dogged Pioneer enters, create a 2/2 green Hound creature token.
Whenever a land you control enters, put a +1/+1 counter on Dogged Pioneer and up to one target Hound.