msem-instigator

Goblin Exploration Team gets +1/+0 for each non-Mountain land you control.

When Goblin Rocktosser enters, you may sacrifice a land. If you do, put a +1/+1 counter on Goblin Rocktosser.

Hidden Prowess deals 2 damage to target creature. When that creature dies this turn, create a 1/1 red Elemental creature token.

{4}{R}, Sacrifice Lavahurler: It deals 5 damage to target player or planeswalker.

Experience (Whenever this creature attacks, if it has fewer than three +1/+1 counters on it, put a +1/+1 counter on it.)
Whenever a +1/+1 counter is put onto Lerithan Rebel, it deals 1 damage to any target.

{R}: Phyrexian Firemaster gains haste until end of turn.

Pyre Trap deals 2 damage to any target.
Spell mastery — If there are two or more instant and/or sorcery cards in your graveyard, Pyre Trap deals 4 damage instead, and you may cast it as though it had flash.

Whenever another Goblin you control attacks, you may pay {1}. If you do, it gets +1/+0 until end of turn.

Prowess

Whenever you cast a noncreature spell, Sara, Entelan Elementalist gets +X/+0 until end of turn, where X is Sara's power. It deals 1 damage to each creature you don't control.

Prowess
Whenever you cast an instant or sorcery spell, Tirenan Pyromancer deals 1 damage to each opponent.

Create two 1/1 red Elemental creature tokens.
Spell mastery — If there are two or more instant and/or sorcery cards in your graveyard, you may change the targets of up to one target spell or ability.

When Artian, Phyrexian Architect enters, search your library for a land card, put it onto the battlefield, then shuffle.
At the beginning of your upkeep, put a corruption counter on a land you control. Then create a 1/1 colorless Phyrexian artifact creature token for each land you control with a corruption counter on it.

Put a number of +1/+1 counters on target creature you control equal to that creature's power.
Spell mastery — If there are two or more instant or sorcery cards in your graveyard, you may have that creature fight another target creature. (Each deals damage equal to its power to the other.)

Whenever another creature you control dies, put a +1/+1 counter on Deathfeeder.
Sacrifice Deathfeeder: Target creature gets +X/+X until end of turn, where X is Deathfeeder's power.

When Defiant Bristles dies, put a +1/+1 counter on target creature.

Target creature you control gets +5/+5 until end of turn.
Spell mastery — If there are two or more instant and/or sorcery cards in your graveyard, destroy up to one target artifact.

{G}: Each player exiles a card from their graveyard. If an instant or sorcery card is exiled this way, put a +1/+1 counter on Earthfeeder Worm.
Remove X +1/+1 counters from Earthfeeder Worm and sacrifice it: Exile X target cards from graveyards.

Elemental Envelopment enters with X +1/+1 counters on it.
When Elemental Envelopment enters, if you controlled a green legendary creature or planeswalker as you cast it, search your library for any number of Elemental creature cards with total mana value X or less, where X is Elemental Envelopment's power, put them onto the battlefield, then shuffle.

When Elvish Skyranger enters, search your library for a card with a basic land type, put it onto the battlefield tapped, then shuffle.

Whenever you play a land, you may put a land card from your hand onto the battlefield tapped.

When Forest Whale dies, put a number of +1/+1 counters on target creature you control equal to Forest Whale's power.

Forestheart Elemental enters with a +1/+1 counter on it for each land you control.

Interan Soothsayer gets +1/+1 for each other green creature you control.
{G}, {T}: Put a +1/+1 counter on target green creature.

Put two +1/+1 counters on target creature. You gain life equal to that creature's power.