msem-instigator

When Arpechian Stag enters, create a 3/3 red Elk creature token with haste, a 3/3 green Elk creature token with trample, and a 3/3 white Elk creature token with vigilance.

This spell can't be countered.
Survivor spells you cast can't be countered.
Whenever a nontoken Survivor you control enters, create a tapped 1/1 Survivor creature token that's all colors.

At the beginning of combat on your turn, target creature you control has base power and toughness 5/5 until end of turn.

Creature spells you cast cost {1} less to cast.
Whenever you cast a creature spell, Bellowing Thoctar gets +2/+2 until end of turn.

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.

If you would draw a card, you may instead choose creature or land and exile cards from the top of your library until you exile a card of the chosen kind. Put that card into your hand and put all other cards exiled this way on the bottom of your library in a random order.

Flying
Whenever a permanent you control becomes the target of a spell or ability you don't control, choose one —
• Create a 3/3 red Manticore creature token.
• Create two Treasure tokens.
• Draw a card.

When Div of Bonded Souls enters, create a 1/1 colorless Illusion creature token with “This creature is every creature type.”
Whenever a creature you control attacks, it gets +1/+0 until end of turn for each other attacking creature that shares a creature type with it.

Whenever Dunesea Dreadstalker or another nontoken creature you control dies, 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 basic land card, put that card onto the battlefield tapped, then shuffle. Create three 1/1 Scout creature tokens that are all colors.

Improve {R} ({R}: Put a +1/+1 counter on this creature. This costs {1} more to activate for each +1/+1 counter on it. Improve only as a sorcery.)
Whenever another creature you control with power less than or equal to Folkvar, Galdurheim Brawler's power attacks, Folkvar deals 1 damage to the player or planeswalker that creature is attacking and you gain 1 life.

If a source you control would deal exactly 1 damage to a permanent or player, it deals 3 damage instead.

At the beginning of your upkeep, you may discard a card. If you do, draw a card.
{T}: You may put a creature card from your hand onto the battlefield. If you do, put a +1/+1 counter on that creature.

Vigilance, trample
Each creature you control can't have power less than its toughness. (If it would have less, it has as much as its toughness instead.)
Each creature your opponents control can't have toughness greater than its power.

When Graide, Voice of Autumn enters, create X 1/1 green Squirrel creature tokens.
Squirrels you control get +1/+0 and have haste.
Nonbasic lands your opponents control enter tapped.

Trample
Other Dwarves and Elves you control get +1/+1.
If Harl and Finn or another Dwarf or Elf you control entering the battlefield or attacking causes a triggered ability of a permanent you control to trigger, that ability triggers an additional time.

[+2]: Until end of turn, up to one target creature you control gets +3/+3 and gains trample and vigilance.
[–2]: Destroy target artifact, enchantment, or tapped creature.
[–3]: Create a 1/1 green Insect creature token, a 2/2 white Cat creature token, and a 3/3 red Ox creature token.
[–8]: Until end of turn, creatures you control get +X/+X and gain trample and vigilance, where X is the number of creatures you control.

At the beginning of your upkeep, rouse 1. Then if you control a creature with power 5 or greater, put a +1/+1 counter on each creature you control. (Put a +1/+1 counter on a permanent you control. If it isn't a creature, tap it and it becomes a 0/0 creature in addition to its other types.)

I — Create a 1/1 green Insect creature token.
II — Create a 2/2 white Cat creature token.
III — Create a 3/3 red Ox creature token.
IV — Creatures you control gain vigilance and indestructible until end of turn.

Vigilance
Whenever another creature you control attacks, put a +1/+1 counter on it if it has less than 4 power. Otherwise, it gains first strike and trample until end of turn.

Each player may play an additional land on each of their turns.
Whenever a land enters, each player may draw a card.

Choose two —
• Put three +1/+1 counters on target creature.
• Target player searches their library for up to two basic land cards, reveals those cards, puts one onto the battlefield tapped and the other into their hand, then shuffles.
• Target creature you control fights target creature you don't control.
• Target player gains 5 life.

Green creatures you control have “{T}: Add one mana of any color.”
Red creatures you control have “{1}, {T}: This creature deals 1 damage to target player.”
White creatures you control have “{2}, {T}: Tap target nonland permanent.”

First strike
Prevent all damage that would be dealt to creatures you control by sources with greater mana value.
{2}{W}{W}: Create a 1/1 colorless Construct Actor creature token. Put a vigilance counter on it.

Flash
Excess damage Polarity Sage would deal to an attacking creature is dealt to that creature's controller instead.