When Promising Future reveals Charm (which moves a unit and triggers a showdown) and Discipline, does the showdown happen immediately when Charm resolves, or after all Promising Future cards have resolved?

Ruling: A showdown only happens when the chain is empty. Promising Future must fully resolve first, then all revealed cards resolve in order, and only after everything resolves does the showdown occur.

Sequence:

• Promising Future resolves and puts both players' revealed cards onto the chain as pending
• Discipline resolves
• Charm resolves (moving the unit)
• After the chain is empty, the showdown occurs

Nuances:

• The cards are placed on the chain in order but only start resolving after Promising Future itself is resolved
• Player B's card and Player A's card are put onto the chain as pending by Promising Future