Search your library for a card, put it into your hand, then shuffle.
Flashback—{1}{B}, Discard a card, Sacrifice a creature.

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.

Untap any number of target creatures. They gain flying and protection from noncreatures until end of turn.

{T}: Add {C}.
Whenever Unwavering Gates attacks, other creatures you control gain indestructible until end of turn.
Spellcharge 5

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.

Valley Caravan's power and toughness are each equal to the number of creatures you control.
Wander {3}{W}{W}
When Valley Caravan enters, if it wandered, create a 1/1 white Human creature token.

Whenever a creature an opponent controls becomes tapped, if it isn't being declared as an attacker, you may draw a card.
{4}{U}: Tap target creature without flying.

As an additional cost to cast this spell, tap any number of untapped creatures you control.
Target creature gets +X/+0 and gains first strike until end of turn, where X is the total power of creatures tapped to pay this spell's additional cost.

Approval — Counter target noncreature spell unless its controller pays {X}, where X is the number of colors among permanents you control.

Vigorous Soundvein enters tapped.
When Vigorous Soundvein enters, you may pay 1 life. If you do, add one mana of any color other than green.
{T}: Add {G}.

Vishanki District enters tapped unless you control a Swamp, a Mountain, and a Forest.
{T}: Add {B}, {R}, or {G}.

Mill two cards, then return a creature card from your graveyard to your hand.
Surface {3}{B}

Flying
When Warcast Seraph enters, put a +1/+1 counter on each other artifact creature you control.

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.

Landfall — Whenever a land you control enters, each opponent loses 1 life.

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.

When Wayward Drek enters, create a 1/1 colorless Cyborg artifact creature token.
Cybersoul {3}{W/B}

{T}: Add {C}.
{T}: Add one mana of any color. If you don't control a Weather, spend this mana only to cast a Weather spell.

{1}, {T}: Target permanent you control becomes an artifact in addition to its other types until end of turn.
Sacrifice Welding Rig: Target artifact gains indestructible until end of turn.

At the beginning of combat on your turn, if you've spent at least five mana to cast spells this turn, creatures you control get +1/+1 and gain trample until end of turn.

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.

Tap up to one target creature. Creatures you don't control don't untap during their controllers' next untap step.
Flashback {4}{U}

Trample
Whenever Wolf-Whistle Satyr deals combat damage to a player or planeswalker, you may sacrifice it. If you do, bless target creature you control.

When Worshipped Diva enters, if a creature died this turn, create a 2/1 red Zombie creature token with menace.