msem-instigator

Desert Temple enters tapped.
As Desert Temple enters, an opponent of your choice chooses Oasis or Desiccation.
• Oasis — {T}: Add one mana of any color.
• Desiccation — {T}: Add {C}{C}. You lose 1 life.

Whenever Canyon Mystic deals combat damage to a player, draw a card.

Vanguard — Whenever a creature you control attacks alone, gain control of target nonland permanent for as long as you control The Rocket Gang Strikes!.

Whenever you draw a card, put a +1/+1 counter on Highborn Meditant.

Chosen one ({W}{U}{B}{R}{G}: Transform this permanent.)
At the beginning of combat on your turn, create a 1/1 red Warrior creature token with haste. That token attacks this combat if able.

Double your life total. (Then exile this card. You may cast the creature later from exile.)

Cannonblast deals 5 damage to target creature. If you control a Pirate, Cannonblast deals 3 damage to that creature's controller.

This spell can't be countered.
{U}: Exile Skulkling. Return it to the battlefield under its owner's control at the beginning of the next end step.
{1}{U}: Until end of turn, Skulkling gets +1/-1 and can't be blocked.
{3}{U}: Draw a card. Create a 1/1 blue Rogue creature token.

Target player mills three cards for each artifact you control.

Destroy target artifact or enchantment. If you controlled that artifact or enchantment, draw two cards.

When Sandbluff Barflies enters, you gain 2 life.

({T}: Add {W}.)
As Calcified Dunes enters, you may pay 1 life. If you don't, Calcified Dunes enters tapped.

When Scrapgear Contraption dies, you may put a +1/+1 counter on target creature.

Determined Chevalier has vigilance as long as it's embattled. (A creature is embattled if it has a counter on it or a permanent you control attached to it.)

Menace
When Blackmoat Bully dies, put a +1/+1 counter and a menace counter on target creature you control.

Until end of turn, target creature gets +2/+2 and gains “Whenever this creature attacks, you may post a bounty on target creature.” (Put a bounty counter on that creature. It has “When it dies, each opponent draws a card” as long as it has a bounty counter on it.)

Haste
Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)
If a player casting a noncreature spell would cause an ability of a permanent you control to trigger, that ability triggers an additional time.

Whenever Ujuraq, Elder Watcher enters or attacks, surveil 1. (Look at the top card of your library. You may put that card into your graveyard.)
Ujuraq gets +3/+3 and has trample as long as there are eight or more cards in your graveyard.

Flying
When Windrider Elemental enters, target creature gains flying until end of turn.

Gain control of up to two target creatures until end of turn. Untap them. They gain haste until end of turn.
Menagerie — If there are five or more creature types among creatures you control, untap all creatures you control. Until end of turn, they gain “{T}: This creature fights another target creature.”

[+1]: Tap target nonland permanent. It doesn't untap during its controller's next untap step.
[–2]: Exile target tapped nonland permanent.
[–4]: Target player skips their next untap step. Tap up to three target permanents.

Enchant creature you control
When Nylea's Benefaction enters, scry 2.
Enchanted creature gets +3/+3 and has reach.

{T}, Sacrifice a creature: Return target creature card from your graveyard to your hand.
{T}, Sacrifice an artifact: Planar Processor deals 1 damage to any target.
{T}, Sacrifice an enchantment: Draw a card.
{T}, Sacrifice a land: Add one mana of any color.

Target creature gets +2/+1 and gains trample until end of turn. Create a tapped Treasure token. (It's an artifact with “{T}, Sacrifice this artifact: Add one mana of any color.”)