Concoct Disorder (Red)

When this attacks, each hero puts the top card of their deck face-down into their arsenal. If 2 or more cards are put into arsenals this way, this gets go again.

Rulings

From the Compendium of Rathe release notes

Concoct Disorder triggers when it resolves on the stack and becomes an attacking card on the combat chain. When the triggered effect resolves, each hero puts the top card of their deck face-down into their arsenal, beginning with you and moving clockwise around the table. If 2 or more cards are put into arsenals this way, Concoct Disorder gets go again.
If a hero is unable to put a card in their arsenal, that effect fails for that hero.
When resolving Concoct Disorder’s triggered effect, there is no priority between any of the effects generated (e.g. each hero putting the top card of their deck face-down into their arsenal, getting go again).

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)