msem-instigator

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.

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

Breach (Whenever this deals combat damage to a player, you may have it become an Aura Curse until your next turn. Attach it to that player.)
Once each turn, when a Curse you control becomes attached to an opponent, you may sacrifice it. If you do, reveal cards from the top of your library until you reveal a Curse card. Put that card onto the battlefield attached to that player, and the rest on the bottom of your library in a random order.

Whenever Fleshwarper or another Horror you control dies, each opponent loses 1 life and you gain 1 life. You may mill a card.

When Fleshwrithe Ghoul enters the battlefield, each player sacrifices a creature.
Revive {4}{B} ({4}{B}, Exile this card from your graveyard: Create a token that's a copy of it except it has no mana cost. Revive only as a sorcery.)

When Fletcher Kalku enters the battlefield or attacks, you may exile a card from your hand face down. If you do, draw a card.
You may look at cards exiled with Fletcher Kalku.
{U}{U}, Reveal a card exiled with Fletcher Kalku: Counter target spell if it has the same mana value as the revealed card. Then put the exiled card into its owner's hand.

Lifelink
Pay 3 life: Flightful Fledgling gains flying until end of turn.

Whenever another creature enters the battlefield under your control, Flightpath Trainee gains flying until end of turn.

First strike
Whenever Flintlock Pioneer deals damage, tap it. It doesn't untap during its controller's next untap step.

Heroic — Whenever you cast a spell that targets Floodspeaker Triton, put a +1/+1 counter on Floodspeaker Triton, then scry 1.

Reach, trample
Whenever this creature transforms into Flourishing Companion or attacks, untap all lands you control.

Once each turn, when you activate a nonmana ability, you may tap target creature.
{1}{U}: Foggy Town Militia gains flying until end of turn.

When Forerunner of the Briar enters the battlefield, sacrifice two lands. When you do, choose one —
• Create a 3/3 green Beast creature token.
• Search your library for up to two basic land cards, put them onto the battlefield tapped, then shuffle.

When Forest Whale dies, put a number of +1/+1 counters on target creature you control equal to Forest Whale's power.

{W}{W}, Exile a legendary creature card from your graveyard: If Forgotten Heir is a Peasant, it becomes a Human Noble Knight with base power and toughness 3/3, lifelink, and vigilance.

At the beginning of each combat, target creature you control gets +3/+3 until end of turn.
Revive {2}{B}{R}{G} ({2}{B}{R}{G}, Exile this card from your graveyard: Create a token that's a copy of this card, except it has no mana cost. Activate this ability only any time you could cast a sorcery.)

Menace
When Fortune Hoarder dies, each player discards a card at random.

Civilized — Whenever Founding Hero attacks, if you control an artifact, a creature, and an enchantment, Founding Hero gains double strike until end of turn.

Haste

{1}{R}{W}: Create a 2/1 red and white Fox creature token. It gains haste. Sacrifice it at the beginning of the next end step.
Whenever Fox of a Brisk Autumn attacks, attacking Foxes you control get +1/+1 until end of turn.

Other Foxes you control get +1/+1.
{2}{W}: Target Fox you control gains lifelink until end of turn.

At the beginning of your end step, if a creature you controlled died this turn, put a +1/+1 counter on Fox of an Amber Dawn.

When Fox of the Juniper Vale enters the battlefield, create an Idol token. (It's an artifact with “{1}, Sacrifice this artifact: Put a +1/+1 counter on target creature. Activate only as a sorcery.”)