Promise of Plenty (Red)

When this hits, each hero who doesn't have a card in their arsenal puts the top card of their deck face-down into their arsenal.

If this was played from arsenal, it gets go again.

Rulings

From the Crucible of War release notes

You can respond to the ability by playing the card from arsenal (e.g. an instant) to make the arsenal empty before it resolves.

Keyword notes

Go again - Go again allows multiple actions to be played in a turn when usually playing an action with use up your action point, and therefore end your turn. A card with go again gives the controller of that card or activated ability 1 action point when it resolves.

When an action with go again resolves, its controller gains 1 action point.
Multiple instances of go again on the same card or activated ability do not stack. If a card or activated ability has multiple instances of go again when it resolves its controller gains 1 action point only.
If an action with go again does not resolve, its controller does not gain 1 action point.
You cannot reveal a card with no to Belittle. The card must have a value to its power that is 3 or less. (0 is a value)