msem-instigator

Unveil {3}{G}{W} ({3}{G}{W}: Transform this. Unveil only as a sorcery.)

Whenever a creature attacks Kalro, Desert Outpost, it deals 1 damage to that creature.
[+1]: Create a 1/1 red and white Sand Warrior creature token.
[–2]: Destroy target nonbasic land. Its controller creates a colorless Desert land token with “{T}: Add {C}.”

Target creature gets +2/+2 and gains trample until end of turn.
Reprise {2}{R} (As you cast an instant or sorcery spell, you may exile one card with reprise from your graveyard and pay its reprise cost. If you do, add its effects to that spell.)

{2}: Add one mana of any color.

Destroy target creature. Create a tapped Treasure token.

Flying, vigilance
As Archon of the Accord enters, choose a number.
Spells with mana value equal to the chosen number can't be cast.

Search your library for up to six cards and exile them face down. Shuffle, then draw a card.

Vigilance
When Lagonna-Band Mentor enters, create a 1/1 white Soldier creature token.

All damage that would be dealt to target creature you control this turn is dealt to another target creature you control instead. Both those creatures get +1/+1 until end of turn.
Flashback {1}{W} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

When Miede-District Alchemist enters, add {R}{R}{R}.
Paranoia {1}{R} (You may cast this spell for its paranoia cost when a permanent you control leaves the battlefield.)

Sacrifice Scrapyard Raiders: Target artifact gains indestructible until end of turn.

This spell costs {3} less to cast if it targets a card in your graveyard that was put there from anywhere this turn.
Exile target instant or sorcery card in your graveyard with mana value X or less. You may cast a copy of that card without paying its mana cost.

Shimmer (Whenever this creature attacks, create a tapped and attacking token that's a copy of it. Exile the token at the beginning of the end step.)

Create X 1/1 blue Boar Dragon creature tokens with flying. (Then exile this card. You may cast the creature later from exile.)

Flying
Deploy 2 (As this enters, you may tap any number of other creatures you control with total power 2 or more.)
When Ethereal Shepherd enters deployed, exile target creature. That creature's controller creates a 1/1 white Spirit creature token with flying.

Draw three cards. Discard your hand at the beginning of the next end step.

Creatures have “Whenever this creature attacks or blocks, it fights another target creature.”

When Whiterun Ordainer enters, you gain 4 life.

Whenever Aukashi, Electric Legacy enters or equipped creature dies, attach Aukashi to a creature you control.
Whenever equipped creature deals damage to a permanent or player, Aukashi deals 2 damage to that permanent or player.
Equipped creature has double strike as long as a creature you controlled died this turn.
Equip {2}

Whenever a creature you control attacks, you may sacrifice a Treasure. If you do, that creature can't be blocked this turn.

Blessed Barrage deals 5 damage divided as you choose among any number of attacking or blocking creatures.

When Hardlight Visionary enters, create a Function token with “Until end of turn, target creature becomes a 5/5 Dragon and gains flying.” (It's an enchantment. As you cast an instant or sorcery spell, sacrifice any number of Functions to add their effects to that spell.)

Destroy each artifact with mana value X or less, then create an Idol token for each artifact destroyed this way. (It's an artifact with “{1}, Sacrifice this artifact: Put a +1/+1 counter on target creature. Activate only as a sorcery.”)

Flying (This creature can't be blocked except by creatures with flying or reach.)
Whenever Mindscreech Drake deals combat damage to a player, that player mills three cards.

Search your library for a creature card, reveal it, then shuffle and put that card second from the top.