You may pay {1}{B} rather than pay this spell's mana cost. When you do, target opponent creates two 1/1 white Citizen creature tokens.

Vigilance
Landfall — Whenever a land you control enters, you may discard a card. If you do, draw a card.
{R}{W}: You may play land cards from your graveyard this turn.

Dormant Monstrosity enters tapped with three stun counters on it.
{1}{U}, Remove a counter from Dormant Monstrosity: Draw a card.

Defender
Whenever you cast an instant or sorcery spell, Dormant Slagheap loses defender until end of turn. If that spell was cast from your graveyard, put a +1/+1 counter on Dormant Slagheap.

Target creature gets -2/-2 until end of turn. Its controller mills two cards.

When this creature enters, create a white Subroutine enchantment token named ALARM with “Whenever this Subroutine runs, create a 1/1 white Citizen creature token.”

This spell costs {2} less to cast if you control a creature with a level counter on it.
Flying

Damned — Destroy target creature if it has mana value 3 or less or if you've sacrificed a permanent this turn.

Target creature gets +2/+0 and gains first strike until end of turn. If it's a Dragon, put a +1/+1 counter on it.

Flying
When this creature enters, if it was cast, return up to three target creature cards with total mana value 3 or less from your graveyard to the battlefield.

Whenever you discard a card, you may have this enchantment become a 3/3 Dragon creature with flying in addition to its other types until end of turn.
{U}, Sacrifice this enchantment: Return target card you discarded this turn from your graveyard to your hand.

This spell costs {1} less to cast if you control a creature with flying.
Return target nonland permanent to its owner's hand.

Create a 1/1 white Human creature token, then put a +1/+1 counter on each creature you control.
Flashback {5}{W}

Fabric — Target creature you control gets +X/+X until end of turn, where X is the number of enchantments you control. It deals damage equal to its power to up to one target creature you don't control.

When Dream Catcher enters, return target exiled card with flashback you own to your hand.

{T}: Integrate the top card of target player's library.
{B}, Sacrifice Dregstreet Inquisitor: Target player loses life equal to the number of cards integrated onto Dregstreet Inquisitor.

Create two 1/1 colorless Thopter artifact creature tokens with flying, then each Thopter you control deals 1 damage to each opponent.

Menace
Swampcycling {2}

When Dryad of the Keen-Eyed enters, search your library for a basic Forest card, reveal it, and put it into your hand. If your devotion to green is three or greater, put it onto the battlefield tapped instead.

Target opponent reveals their hand. You choose a noncreature, nonland card from it. That player discards that card.

Flying
Amity — Whenever you attack with Dustwing Butterfly and exactly one other creature, create a tapped and attacking token that's a copy of target creature you control, except it's 1/1 and isn't legendary. Sacrifice that token at the beginning of the next end step.

Flying
Amity — Whenever you attack with Dustwing Moth and exactly one other creature, Dustwing Moth deals 2 damage to any target.

As an additional cost to cast this spell, sacrifice a creature or exile two permanent cards from your graveyard.
Draw two cards.

Dynamo Glyphs enters with six minus X charge counters on it.
Whenever a creature you control attacks, remove a charge counter from Dynamo Glyphs. Then if it has no charge counters on it, sacrifice it. If you do, draw three cards.

Whenever you cast a multicolored spell, you gain 1 life.
{T}: Add one mana of any color.