Reciprocate

Exile target creature that dealt damage to you this turn.

Midnight Guard

Whenever another creature enters, untap Midnight Guard.

Open the Armory

Search your library for an Aura or Equipment card, reveal it, put it into your hand, then shuffle.

Social Climber

Alliance — Whenever another creature you control enters, you gain 1 life.

Plains

Gaze of Justice

As an additional cost to cast this spell, tap three untapped white creatures you control.
Exile target creature.
Flashback {5}{W} (You may cast this card from your graveyard for its flashback cost and any additional costs. Then exile it.)

Forest

Instrument of the Bards

At the beginning of your upkeep, you may put a harmony counter on Instrument of the Bards.
{3}{G}, {T}: Search your library for a creature card with mana value equal to the number of harmony counters on Instrument of the Bards, reveal it, and put it into your hand. If that card is legendary, create a Treasure token. Then shuffle.

Heliod's Pilgrim

When Heliod's Pilgrim enters, you may search your library for an Aura card, reveal it, put it into your hand, then shuffle.

Wall of Omens

Defender
When Wall of Omens enters, draw a card.

Elegant Entourage

Alliance — Whenever another creature you control enters, target creature other than Elegant Entourage gets +1/+1 and gains trample until end of turn.

Presence of Gond

Enchant creature
Enchanted creature has "{T}: Create a 1/1 green Elf Warrior creature token."