msem-instigator

Assault {X}{R}{R} (Whenever this attacks, if it has no +1/+1 counters on it, you may pay its assault cost to put a +1/+1 counter on it.)
Other Elementals you control get +1/+0.
When Unbound Annihilus assaults, create X 1/1 red Elemental creature tokens that are tapped and attacking.

Haste
When Urud Stingswoop enters, it gains flying until end of turn.

Assault {1}{R} (Whenever this attacks, if it has no +1/+1 counters on it, you may pay its assault cost to put a +1/+1 counter on it.)
When Urudi Warlord assaults, it gains first strike until end of turn.

I, II — Search your library for a basic land card, reveal it, put it into your hand, then shuffle.
Discovery — {4}: You gain 2 life.

{G}, {T}, Remove a +1/+1 counter from a creature you control: Create a 2/2 green Ox creature token.

Assault {1}{G} (Whenever this attacks, if it has no +1/+1 counters on it, you may pay its assault cost to put a +1/+1 counter on it.)
When Caprin Outlander assaults, you gain 3 life.

Destroy target artifact or enchantment with mana value 4 or less.

Assault {3}{G} (Whenever this attacks, if it has no +1/+1 counters on it, you may pay its assault cost to put a +1/+1 counter on it.)
When Crushclaw Pulverizer assaults, you may destroy target artifact or enchantment.

Prevent all combat damage that would be dealt this turn except by creatures you control with +1/+1 counters on them.

Assault {1}{G} (Whenever this attacks, if it has no +1/+1 counters on it, you may pay its assault cost to put a +1/+1 counter on it.)
When Dune Tromper assaults, it gains trample until end of turn.

Choose one —
• Target creature you control deals damage equal to its power to another target creature or planeswalker.
• Target planeswalker you control deals damage equal to the number of loyalty counters on it to target creature or planeswalker.

Choose X. You may choose the same mode more than once.
• Put two +1/+1 counters on target creature you control.
• Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.
• Destroy target artifact or enchantment.

Mill three cards, then you may return a creature or land card from your graveyard to your hand. (To mill three cards, put the top three cards of your library into your graveyard.)

As an additional cost to cast this spell, sacrifice a land.
Search your library for up to two basic land cards, put them onto the battlefield, then shuffle.

Target permanent you control gains hexproof until end of turn. If that permanent is a creature, it also gets +1/+1 until end of turn.

This spell can't be countered.
Enchant land
At the beginning of combat on your turn, untap enchanted land. It becomes a 6/6 green Lizard creature with haste until end of turn. It's still a land.

When Humble Shepherd enters, create a 0/1 white Sheep creature token.
{T}, Tap an untapped Sheep you control: Add one mana of any color.

I, II — Create a 3/3 green Beast creature token with defender.
Discovery — Creatures you control with defender can attack as though they didn't have defender.

Enchant land
Enchanted land has “{T}: Put a +1/+1 counter on target creature you control. Activate only as a sorcery.”

{T}: Add {C}.
{1}, {T}: Add one mana of any color.

Whenever a nontoken creature you control enters, if it shares no creature types with other creatures you control, draw a card.

When Naga Cultivator enters, you may put a land card from your hand onto the battlefield.

Rhudai Fieldtiller gets +1/+1 for each enchanted land you control.
At the beginning of your end step, untap each enchanted land you control.

{1}{G}: Rhudai Pathfinder gets +X/+X until end of turn, where X is the number of differently named lands you control. Activate only once each turn.

Whenever Rhudai Swathcutter attacks, you may search your library for a basic land card, put it onto the battlefield tapped, then shuffle.