msem-instigator

This spell costs {1} less to cast for each +1/+1 counter among creatures you control.
Hoof Cliff Heartminer enters with four +1/+1 counters on it.
Whenever Hoof Cliff Heartminer or another creature you control leaves the battlefield, you may put its +1/+1 counters on another target creature you control.

Horizon Wayfarer's power and toughness are each equal to the number of differently named lands you control.

You may have Illusion of the Div enter as a copy of any creature you control except it has “{G}{U}{B}, Discard a card: Create a tapped token that is a copy of this creature.”

You may have Imitator of Success enter as a copy of any creature on the battlefield, except it has no mana cost and base power and toughness 1/1 if it's a token.
Successor {1}{U}{U} ({1}{U}{U}, Exile this card from your graveyard: Create a token that's a copy of this card, except it has no mana cost and base power and toughness 1/1. Succeed only as a sorcery.)

At the beginning of each opponent's end step, that player gets a poison counter unless damage was dealt this turn.

Defender
When Immured Fiend enters, target opponent discards two cards.

{U}, Sacrifice Imperious Nixie: Return target creature to its owner's hand.

Flash
Defender
When Imposing Barricade enters, target creature doesn't untap during its controller's untap step for as long as you control Imposing Barricade.

Whenever Infernal Barrier is dealt damage, it deals 1 damage to each opponent.

Graft 1 (This creature enters with a +1/+1 counter on it. Whenever another creature enters, you may move a +1/+1 counter from this creature onto it.)
{T}: Add {C}.

You may have Insipid Metamorph enter as a copy of any other creature on the battlefield, except it's 1/1.

Flying, ward {1}
Intisuyu's Masterpiece gets +X/+X, where X is the number of artifacts and/or enchantments you control.

{T}: Add {G}.
{T}: Add one mana of any color. Activate only if you control another Dryad.

Protection from mana values lower than Ironwood Elemental's power (This permanent can't be blocked, targeted, dealt damage, or enchanted by anything with mana value lower than this creature's power.)
Ironwood Elemental's power and toughness are each equal to the number of creatures you control.

Transcend (Activate as a sorcery to gain the next type and a +1/+1 counter.)
Jutou enters with X +1/+1 counters on her.
{3}{G}: Demigod — You gain life equal to the greatest power among creatures you control.
{6}{G}: God — Search your library for a creature card with the same power as a creature you control, put it onto the battlefield, then shuffle.

When Kahroba General enters, recruit. (Create a 0/0 white Soldier Army creature token, then put a +1/+1 counter on each Army you control.)
Kahroba General gets +1/+1 for each creature you control.

At the beginning of your upkeep, put a +1/+1 counter on Kaur's Gift, then you gain life and add {G} equal to its power. You don't lose that mana as steps, phases, and turns end.
When Kaur's Gift dies, you gain life and add {G} equal to its power. You don't lose that mana as steps, phases, and turns end.

{T}: Scry 1.
{1}{U}, {T}: Reveal the bottom card of your library. If it's an artifact or enchantment card, put it into your hand.

As an additional cost to cast this spell, return any number of creatures you control to their owner's hands. This spell costs {2} less to cast for each creature returned in this way.
Trample, ward {3}
Keepers of the Rundfora's power and toughness are each equal to twice the number of cards in your hand.

When Kofe-District Scholar enters, draw a card. If Kofe-District Scholar's paranoia cost was paid, draw two cards instead.
Paranoia {1}{U}{U} (You may cast this spell for its paranoia cost when a permanent you control leaves the battlefield.)

Experience (Whenever this creature attacks, if it has fewer than three +1/+1 counters on it, put a +1/+1 counter on it.)
Remove a +1/+1 counter from Kor Skyknight: It gains flying until end of turn.

First strike, haste
Whenever Kragnoss' Battlecharger attacks, it gets +1/+0 until end of turn for each attacking creature.

Shimmer (Whenever this creature attacks, create a tapped and attacking token that's a copy of it. Exile the token at the beginning of the end step.)
Lha Elite's power is equal to the number of tokens you control.

Whenever Lha Maria blocks a creature, change Lha Maria's base power and toughness to that creature's power and toughness

Whenever a token enters, you may have it become a 3/3 green Elemental creature.