Does a showdown occur mid-chain if one player moves a unit away from a battlefield and another player reacts by moving a unit to that same battlefield?

Ruling: Showdowns do not occur mid-chain. The chain must fully resolve before a showdown starts.

Sequence:

• Player A uses a spell to move their unit from battlefield back to base
• Player B reacts by moving a unit to the same battlefield
• The chain resolves completely
• After chain resolution, a showdown occurs where Player B attempts to conquer the now-open battlefield while Player A's unit is at base