Does a showdown continue after all units are removed from the battlefield, and can actions still be played?

Ruling: Once a showdown starts, it continues until both players pass priority consecutively, even if all units are removed from the battlefield before damage calculation.

Sequence:

• Showdown begins when units meet at a battlefield
• Players can play actions and pass priority
• Showdown ends only when both players pass consecutively
• If units remain from both sides, proceed to damage calculation
• After damage calculation completes, the showdown is over

Nuances:

• If you lose control of a battlefield during the showdown (before damage calculation), you cannot play units to that battlefield - they would be played to base or another controlled battlefield instead
• Once damage calculation has occurred and units kill each other, you are no longer in a showdown and cannot play showdown-specific cards