msem-instigator

Whenever you cast a spell during an opponent's turn, Haughty Priest deals 1 damage to that player.

Haste (This creature can attack and {T} as soon as it comes under your control.)
Mirage {R} (You may cast this spell as though it had flash for its mirage cost. If you do, sacrifice it at the beginning of the next cleanup step.)

Whenever a creature blocks, Heat of Battle deals 1 damage to that creature's controller.

Enchant creature
Enchanted creature gets +2/+0 and has first strike.
Mirage {R} (You may cast this spell as though it had flash for its mirage cost. If you do, sacrifice it at the beginning of the next cleanup step.)

Scry 3, then reveal the top card of your library. Discard your hand, then draw cards equal to that card's mana value.

First strike, haste
When Mounted Marksman enters, it deals 2 damage to target creature you don't control.

Trample
Tribute 3 (As this creature enters, an opponent of your choice may put three +1/+1 counters on it.)
When Rockpounding Saurian enters, if tribute wasn't paid, you may destroy up to one target artifact, up to one target land and up to one target Fortress.

When Sandmouth Dragon enters, another target creature you control gets +3/+0 until end of turn.
Mirage {2}{R} (You may cast this spell as though it had flash for its mirage cost. If you do, sacrifice it at the beginning of the next cleanup step.)

Haste
Sixpod Sprinter can't be blocked except by creatures with flying or reach.

Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)

Creatures you control get +1/+0 and attack each turn if able.
As long as you control four or more Mountains, attacking creatures you control get an additional +1/+0 and have first strike.

Prowess, haste
Mirage {R} (You may cast this spell as though it had flash for its mirage cost. If you do, sacrifice it at the beginning of the next cleanup step.)

As an additional cost to cast this spell, sacrifice a land.
Create a 6/6 red Wurm creature token with “This creature can't be blocked by creatures with flying.”

Put all attacking creatures on top of their owners' libraries.

[+2]: Sacrifice a creature. If you do, you may draw two cards.
[–1]: Gain control of target creature for as long as you control Jachsechep, God's Wife.
[–10]: You get an emblem with “Whenever a creature enters under an opponent's control, gain control of it.”

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}.”

Enchant creature
When Mesmerizing Shimmer enters, untap enchanted creature. It gains haste until end of turn.
You control enchanted creature.
Mirage {2}{U}{R} (You may cast this spell as though it had flash for its mirage cost. If you do, sacrifice it at the beginning of the next cleanup step.)

Destroy target planeswalker. Mummy's Grin deals 2 damage to that planeswalker's controller.

Tribute 4 (As this creature enters, an opponent of your choice may put four +1/+1 counters on it.)
When Slaughter enters, if tribute was paid, destroy all other creatures. Otherwise, destroy all creatures you don't control.

Equipped creature has “You may choose not to untap this creature during your untap step” and “{T}: Gain control of target creature with power 5 or greater for as long as you control this creature and it remains tapped.”
Equip {3}

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.

Enchant creature
When Angel's Favor enters, draw a card.
Enchanted creature gets +0/+2 and has flying.

Prevent all combat damage that would be dealt to Armored Axewarden 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.)

First strike, vigilance
Whenever Asamund, Queen of Yroncaster deals combat damage to a player, choose a number. That player can't cast noncreature spells with mana value equal to the chosen number until the end of your next turn.

Foretell {2}{W}{W} (During your turn, you may pay {2} and exile this card from your hand face down. Cast it on a later turn for its foretell cost.)
Choose one. If this spell was foretold, you may choose both instead —
• Put a +1/+1 counter on each creature you control.
• Exile target nonland permanent an opponent controls. Its controller may scry 2.