msem-instigator

Choose one —
• Destroy target artifact.
• Destroy target enchantment.
• Destroy target creature with flying.

When Sandwurm's Might enters, you may have target creature you control fight target creature you don't control.
Each creature you control enters with an additional +1/+1 counter on it.

Mentor (Whenever this creature attacks, put a +1/+1 counter on target attacking creature with lesser power.)
Whenever Seeker of Ruins deals combat damage to a player, put a +1/+1 counter on it.

Search your library for a Desert card or a land card with a basic land type and put it onto the battlefield tapped, then shuffle.

Whenever you cast a cryptic spell, put a +1/+1 counter on Spiny Lizard. (Artifacts, enchantments, and modal spells are cryptic.)
When Spiny Lizard dies, you gain life equal to its power.

Hexproof
Cycling {3} ({3}, Discard this card: Draw a card.)

You may have Surging Wurm assign its combat damage as though it weren't blocked.
Surging Wurm gets +2/+2 as long as seven or more cards are in your graveyard.

Whenever Titanic Hardshell deals combat damage to a player, draw a card.
{2}{G}: Titanic Hardshell gains trample until end of turn.

Enchant creature
When Tomb Robber's Grit enters, investigate. (Create a colorless Clue artifact token with “{2}, Sacrifice this artifact: Draw a card.”)
Enchanted creature gets +1/+1.

Trained Reptile gets +1/+1 for each enchantment you control.
Trained Reptile can't be blocked by creatures with power 2 or less.

Trample
Mentor (Whenever this creature attacks, put a +1/+1 counter on target attacking creature with lesser power.)
Whenever Tribal Guard mentors a creature, that creature gains trample until end of turn.

As Unlikely Growth enters, choose grow or maintain.
Whenever a land you control enters,
• Grow — Put a +1/+1 counter on target creature you control.
• Maintain — Target creature you control gains trample and indestructible until end of turn.

Whenever Warrior of Far-Off Sands attacks, it gets +1/+1 until end of turn for each creature you control that's enchanted or equipped.

Flying
{T}, Exile two cards from your graveyard: Add one mana of any color.

Vigilance
{X}{G}, {T}: Ylda, the Wild Soul becomes a copy of target creature you control with mana value X, except it has this ability and vigilance. Activate only as a sorcery.

Choose three. You may choose the same mode more than once.
• Put a +1/+1 counter on up to one target creature you control, then you may have it fight target creature you don't control.
• Target player creates a 2/2 green Lizard creature token.
• You mill four cards and gain 4 life.

Flying, prowess
Whenever an artifact you control enters, you may draw a card. If you do, discard a card.

Flying
When Calamity Harbinger enters, it deals 4 damage to up to one target creature or planeswalker.

Menace, haste
Whenever another creature dies, you get a blood counter.
{B}{R}, Pay two blood counters: Return Dthan, Who Bloodies the Sands from your graveyard to the battlefield.

Menace
When The Duneborn Host enters, mill four cards.
Whenever a card is put into your graveyard from anywhere, each opponent loses 1 life and you gain 1 life.
Whenever a card leaves your graveyard, create a 2/2 black Zombie creature token.

Whenever a land you control enters, add one mana of any color.
Whenever Enraged Fangwurm attacks, you may sacrifice a land. If you do, Enraged Fangwurm deals 2 damage to target player or planeswalker.

Flying
As long as you control an equipped creature, Guide of Heroes gets +1/+1 and has first strike.
As long as you control an enchanted creature, Guide of Heroes gets +1/+1 and has vigilance.

Flying, trample
Harbinger of Falling Skies enters with X +1/+1 counters on it.
Whenever Harbinger of Falling Skies attacks, you may remove a +1/+1 counter from it. If you do, draw a card.

Flying
Mentor (Whenever this creature attacks, put a +1/+1 counter on target attacking creature with lesser power.)
Whenever Honorable Mentor mentors a creature, that creature and Honorable Mentor each gain first strike until end of turn.

Flying, vigilance
At the beginning of your end step, if a creature you control dealt combat damage to an opponent this turn, put a +1/+1 counter on Horizon Prophet.