Panharmonicon

If an artifact or creature entering causes a triggered ability of a permanent you control to trigger, that ability triggers an additional time.

Fortune, Loyal Steed

When Fortune enters, scry 2.
Whenever Fortune attacks while saddled, at end of combat, exile it and up to one creature that saddled it this turn, then return those cards to the battlefield under their owner's control.
Saddle 1

Reconnaissance

{0}: Remove target attacking creature you control from combat and untap it. (If you activate during end of combat, the creature will untap after it deals combat damage.)

Felidar Retreat

Landfall — Whenever a land you control enters, choose one —
• Create a 2/2 white Cat Beast creature token.
• Put a +1/+1 counter on each creature you control. Those creatures gain vigilance until end of turn.

Doomed Traveler

When this creature dies, create a 1/1 white Spirit creature token with flying.

Inspiring Overseer

Flying
When this creature enters, you gain 1 life and draw a card.

Hunted Witness

When this creature dies, create a 1/1 white Soldier creature token with lifelink.

Circuit Mender

When this creature enters, you gain 2 life.
When this creature leaves the battlefield, draw a card.

Priest of Ancient Lore

When this creature enters, you gain 1 life and draw a card.

Resolute Reinforcements

Flash (You may cast this spell any time you could cast an instant.)
When this creature enters, create a 1/1 white Soldier creature token.

Countless Gears Renegade

Revolt — When this creature enters, if a permanent left the battlefield under your control this turn, create a 1/1 colorless Servo artifact creature token.

Welcoming Vampire

Flying
Whenever one or more other creatures you control with power 2 or less enter, draw a card. This ability triggers only once each turn.

Storm of Souls

Return all creature cards from your graveyard to the battlefield. Each of them is a 1/1 Spirit with flying in addition to its other types. Exile Storm of Souls.