Goblin Circus

The effect "During each of your End Phases, both players reveal the bottom card of your Deck, and you choose to either place that card on top of your Deck or banish it face-down" creates a Chain Link. (This effect does not target.)

The effect of "Showdown Goblin" is a mandatory effect that must be activated once during each of your End Phases.

After performing the action of "both players reveal the bottom card of your Deck," you choose whether to perform the action of "place that card on top of your Deck" or "banish it face-down." (You choose after both players have confirmed the contents of the bottom card of the Deck. You do not need to declare which action you will perform when activating the effect.)

Cards banished face-down by the effect of "Showdown Goblin" remain banished face-down even if "Showdown Goblin" is no longer on the field, such as if it is destroyed.