msem-instigator

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 on Flamerider, you may have it deal damage equal to its power to target creature.

Flamewhip deals 2 damage to each non-Goblin creature.
If you control a Goblin creature, create a 1/1 red Goblin creature token.

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.

{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

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.

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.)

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.

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.

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.

Reach
Experience (Whenever this creature attacks, if it has fewer than three +1/+1 counters on it, put a +1/+1 counter on it.)
Other Elementals you control get +1/+1 as long as Miroran Skycatcher has a +1/+1 counter on it.

When Mul Daya Elder enters, search your library for a basic land card, put it onto the battlefield tapped, then shuffle.
Whenever a land you control enters, put a +1/+1 counter on Mul Daya Elder.

Perfect Aim deals 5 damage to target creature with flying. When that creature dies this turn, you gain 5 life.

Deathtouch
Whenever a +1/+1 counter is put on a creature you control, that creature gains deathtouch until end of turn.

Experience (Whenever this creature attacks, if it has fewer than three +1/+1 counters on it, put a +1/+1 counter on it.)