msem-instigator

If an opponent controls three or more attacking creatures, you may cast this spell as though it had flash.
Firewall Trap deals 5 damage to target creature. When that creature dies this turn, Firewall Trap deals damage equal to that creature's power to another target creature.

Secretly choose a creature card name. Target opponent chooses a creature you don't control. Firing Blind deals 5 damage to that creature. Reveal the chosen name, then if that creature has the chosen name, Firing Blind deals 3 damage to that opponent.

Destroy target creature. You may remove a counter from up to one target permanent.

Primal {1}{U} (During your turn, you may cast this spell for {1}{U} instead of playing a land.)
Draw two cards.

Destroy target creature or planeswalker. (Then exile this card. You may cast the sorcery later from exile.)

First strike, vigilance
Spells that your opponents cast that target First Wave Explorer cost {2} more to cast.

When Fish Out of Water enters, exile the top four cards of each library.
During each of your turns, you may cast a card exiled with Fish Out of Water without paying its mana cost.

Harness (You may tap a creature you control as you cast this spell. If you do, reduce this spell's mana cost by that creature's power.)
Draw three cards.

Haste
Stampede — Whenever Fissure Bull and a creature with greater power attack, you may sacrifice a land. If you do, search your library for a basic land or Desert card, put that card onto the battlefield tapped, then shuffle.

Enchant creature
When Fists of Ironwood enters, create two 1/1 green Saproling creature tokens.
Enchanted creature has trample.

When Flamboyant Inventor enters, create a tapped colorless Powercell artifact token with “{T}: Add {C}.”
At the beginning of each combat, you may have Powercells you control become 2/2 Construct creatures with vigilance in addition to their other types until end of turn.

When Flame Ascetic enters, you may exile up to one instant card and up to one sorcery card from your graveyard. Put a +1/+1 counter on Flame Ascetic for each card exiled this way.

Flame Jolt deals 2 damage to target creature and 1 damage to target player or planeswalker.

When Flame Juggler dies, it deals 3 damage to each opponent.

Reach
Whenever you cast a noncreature spell, you may pay {R}. If you do, target creature can't block this turn.

Flamebearer's Domain enters tapped.
{T}: Add {R}.

Flameblade deals 4 damage to target player or planeswalker.

When Flameboon Alchemist dies, you may put a +1/+1 counter on target creature you control.

First strike, haste
Whenever you cast an instant or sorcery spell, Flamedaunt Courier gets +2/+0 until end of turn.

First strike (This creature deals combat damage before creatures without first strike.)
Whenever you cast an instant or sorcery spell, Flamemaster Insurgent gets +X/+0 until end of turn, where X is that spell's mana value.

Experience (Whenever this creature attacks, if it has fewer than three +1/+1 counters on it, put a +1/+1 counter on it.)
Whenever a +1/+1 counter is put on Flamerider, you may have it deal damage equal to its power to target creature.

Whenever a creature you control becomes tapped, exile the bottom card of your library. You may put it on top of your library. If you don't, Flames of the Forge deals 1 damage to target opponent or planeswalker.

Enchant creature you control
When Flamespeaker's Craft enters, it deals 2 damage to any target.
Enchanted creature has “{T}, Discard a card: Draw a card.”

Harness (You may tap a creature you control as you cast this spell. If you do, reduce this spell's mana cost by that creature's power.)
Flamethrower deals 4 damage to any target.

Haste
Whenever Flamewake Elk attacks, you may put a +1/+1 counter on another target attacking creature.