Send Packing (Yellow)

When this attacks a hero, banish a card from their arsenal. When the chain link resolves, if this didn't hit, return the banished card to its owner's hand.

Rulings

From the Heavy Hitters release notes

This does not trigger if you attack anything other than a hero (i.e. an ally).
The banished card is banished face-up.
If the player has 2 or more cards in their arsenal, you choose the card to banish.
This effect is distinct from intimidate. The hero attacked is not considered to be intimidated, and you are not considered to have intimidated any hero from this effect.
If the combat chain closes before the chain link resolves, the delayed triggered effect does not trigger and the banished card remains banished.
If the banished card from Send Packing’s triggered effect is turned from face-up to face-down while in the banished zone, the banished card does not return to its owner’s hand.
If the banished card from Send Packing’s triggered effect was moved to another non-stack/arena zone, the card is not returned to its owner’s hand.