Once each turn, when you activate a nonmana ability, you may have creatures your opponents control get -1/-0 until end of turn.
{2}: Unnerving Moth gains flying until end of turn.

When Urban Explorer enters, return a permanent card with mana value 1 or less from your graveyard to your hand.
Landfall — Whenever a land you control enters, Urban Explorer gets +2/+1 until end of turn.

Double strike
Whenever Urban Twinmotors deals combat damage to a player, untap up to one target permanent.

Whenever you gain control of a permanent you don't own or a permanent you don't own enters under your control, put a +1/+1 counter on Vagrant Sorceress.

Whenever you cast an artifact spell, create a 0/0 colorless Robot artifact creature token with a +1/+1 counter on it.
{2}, {T}: Add {R} for each artifact you control. Spend this mana only to cast artifact spells or activate abilities of artifacts.

When Vision Herald enters, the first spell target opponent casts during their next turn costs an additional {1} and 1 life to cast.

{2}, {T}: Scry 1.

Approval — When Warrant-Borne Cop enters, target player reveals X cards from their hand, where X is the number of colors among permanents you control. You choose one of them. That player discards that card.

{T}: Add {C}.
Whenever Wasted Watchpost deals combat damage to a player, you may sacrifice it. When you do, destroy target nonbasic land that player controls.
Spellcharge 3

Artifact spells you cast cost {1} less to cast.
Whenever Waveform Harnessing Unit or another artifact you control enters, target creature gets +1/+1 and gains lifelink until end of turn.

Flying
Whenever Weather Elemental enters or attacks, it acclimates.
If a triggered ability of a Weather you control would trigger, it triggers an additional time.

Lifelink
When Weathered Blackguard enters, you may attach target Equipment you control to it.
Wander {2}{B}

Flying
{2}: Exile the top card of your library face down. You may look at it as long as it remains exiled.
During each of your opponents' turns, you may cast a card exiled with Weaver of Fates as though it had flash.

Flying
When Whipwing Dragonfly enters, you gain 2 life.

Whenever a creature entering the battlefield under your control causes an ability of a permanent you control to trigger, draw a card. This ability triggers only once each turn.

Flying, vigilance
{W}, {T}: Tap target creature.

Trample
Whenever you amp it up, double Xeon, BPM Savant's power until end of turn.

Flying
Amity — Whenever you attack with Zipping Lightningbug and exactly one other creature, target creature you don't control gets -2/-0 until end of turn.

Flying
Whenever you draw your second card each turn, tap target nonland permanent.

Ward—Pay 2 life.
Whenever Zygos attacks, bless target legendary creature you control.

Aethersteel Pouncer enters with a haste counter on it.

Flash
When Agent of Deception enters, counter target creature or planeswalker spell unless its controller pays {X}, where X is your devotion to blue.

When Alluring Queenpin enters, create a 3/3 green Elemental Spirit creature token.
Elementals you control get +1/+1.

Menace
Whenever Aphonai's Reveler attacks, defending player mills two cards. Then if that player has eight or more cards in their graveyard, Aphonai's Reveler gets +2/+1 and gains lifelink until end of turn.

When Arduous Miners enters, you may have all players discard a card.
Whenever one or more cards leave your graveyard, create a tapped Treasure token.