msem-instigator

{T}: Target creature with power 2 or less can't be blocked this turn.

When Goblin Twinblades enters, create a 1/1 red Goblin creature token.

When Golden Grizzly enters, create an Idol token. (It's an artifact with “{1}, Sacrifice this artifact: Put a +1/+1 counter on target creature. Activate only as a sorcery.”)

Target creature gets +2/+2 until end of turn. Whenever that creature deals combat damage to a player or planeswalker this turn, draw that many cards.

Haste (This creature can attack and {T} as soon as it comes under your control.)
Motivate 2 (When this creature enters, you may motivate target creature with less power than this by putting two +1/+1 counters on it.)

When Goriana Earthshaker enters, you may untap target land you control. It becomes a 3/3 Elemental creature with haste until end of turn. It's still a land.

Motivate 2 (When this creature enters, you may motivate target creature with less power than this by putting two +1/+1 counters on it.)
Each creature you control with a +1/+1 counter on it has trample.

Motivate 1 (When this creature enters, you may motivate target creature with less power than this by putting a +1/+1 counter on it.)
When Goriana Tactician enters, you may tap target creature.

Flash (You may cast this spell any time you could cast an instant.)
When Gorillas in the Mist enters, prevent all combat damage that other creatures would deal this turn.

You can't lose the game until your next turn and your opponents can't win the game until your next turn.
Fuse (You may cast one or both halves of this card from your hand.)

Other Dryad creatures you control get +1/+1 and have hexproof.

Flash
If a +1/+1 counter would be put on another creature, that counter is put on Grafted Physician instead.

Equipped creature has “{2}, {T}: This creature deals 1 damage to any target.”
{4}: Untap equipped creature.
Equip {3}

Whenever a creature enters, it fights another target creature of its controller's choice.

Granite Sibyl enters with three +1/+1 counters on it.
Whenever another creature you control enters, move a +1/+1 counter from Granite Sibyl to that creature.

Reach

When Grave Reaper enters, if it wasn't cast from your hand, it gets +1/+1 until end of turn.
Unearth {B} ({B}: Return this card from your graveyard to the battlefield. It gains haste. Exile it at the beginning of the end step or if it would leave the battlefield. Unearth only as a sorcery.)

As an additional cost to cast this spell, exile two cards from your graveyard with the same mana value.
Search your library for a card with the same mana value as the exiled cards, reveal it, put it into your hand, then shuffle.

You may have Graveborn Usurper enter as a copy of any creature card in a graveyard, except it has “{2}{U}{B}, Exile a creature card from a graveyard: Graveborn Usurper becomes a copy of the exiled card, except it has this ability.”

Destroy target creature. If you control a Wizard, put up to one target creature card from your graveyard on top of your library.

Whenever Green Pelt Hart or another Elk creature you control deals combat damage to a player, draw that many cards.

Flying (This creature can't be blocked except by creatures with flying or reach.)
When Griffin Skycaller enters, target creature you control gets +1/+1 and gains flying until end of turn.

As Grim Bastion enters, you may pay 2 life. If you don't, Grim Bastion enters tapped.
{T}, Sacrifice Grim Bastion: Search your library for a Swamp or Forest card, put it onto the battlefield, then shuffle.

Target player sacrifices a creature. Create a tapped 2/2 black Zombie creature token.

{T}, Pay 1 life: Add {B} or {R}.
{1}, {T}, Sacrifice Grim Slums: Investigate. (Create a colorless Clue artifact token with “{2}, Sacrifice this artifact: Draw a card.”)