Whenever you amp it up, creatures you control get +1/+0 until end of turn.

You gain 3 life, scry 2, then draw a card.

Whenever you cast an instant or sorcery spell with mana value 4 or greater, look at the top two cards of your library. Put one of them into your hand and the other into your graveyard.

Ward {1}
Whenever one or more counters are put on Enlightened Naturalist, draw a card for each kind of counter put on it on it that it didn't have already.

Flying, first strike, vigilance

Aura spells you cast cost {1} less to cast.
When Ephara's Oracle enters, look at the top five cards of your library. You may reveal an enchantment card from among them and put it on the top of your library. Put the rest on the bottom of your library in a random order.

Exile target nonland permanent if its mana value is less than or equal to your devotion to white.

{T}, Pay 1 life, Sacrifice an artifact or creature: Make a pledge.

Enchant creature with another Aura attached to it
Enchanted creature gets +3/+3 and has trample, vigilance, and reach.

When Everpresent Rot enters, create a 1/1 green Saproling creature token, surveil 1, then you gain 1 life.
When one or more permanent cards leave your graveyard, return Everpresent Rot to its owner's hand.

Deathtouch
Other Gorgons, Snakes, and Basilisks you control get +1/+1.
Whenever another creature with deathtouch you control deals combat damage to a player or planeswalker, create a Treasure token.

Trample, haste
Decayed

{3}, {T}, Sacrifice Explosive Canister: Explosive Canister deals 3 damage to any target.

Exile the top two cards of your library. You may play those cards until you next cast a spell from your hand.
Flashback {3}{R}{R}

Target creature gets -3/-2 until end of turn.

Creatures can't attack you or a planeswalker you control unless their controller pays {1} for each of those creatures beyond the first.

Target player mills two cards, then mills two more cards for each card named Fathomless Dominion in your graveyard.

Indulgence
Whenever you indulge, choose one —
• Scry 2. Each opponent loses 2 life.
• Create a tapped 2/1 black Rogue creature token with menace.
• Target creature gets -2/-2 until end of turn.

Flash
When Fencer's Foil enters, you may attach it to target creature you control.
Equipped creature gets +2/+0.
Equip {3}

Destroy target creature if its mana value is less than or equal to the amount of mana spent to cast this spell.
Flashback {X}{B}{B}{B}

Final Performance deals 2 damage to target creature. If a creature died this turn, instead Final Performance deals 5 damage to it, and excess damage is dealt to that creature's controller instead.

When Flags on High enters, create two 1/1 colorless Soldier creature tokens.
{1}{R}, Sacrifice Flags on High: Target creature you control gets +1/+0 and gains haste until end of turn. Activate only as a sorcery.

Haste
Whenever a player casts a spell, if no mana from a basic source was spent to cast it, Flaw in the System deals 2 damage to that player.

Return target creature to its owner's hand. If you've cast another instant or sorcery spell this turn, draw a card.

Equipped creature gets +2/+2 and can't be blocked by more than one creature.
Equip {4}