In Riftbound, during a Showdown phase, if my opponent uses a reaction to reduce my attacking unit's might, can I bring up a ready unit from my bench at that point, or must I maintain the number of attacking units?

Ruling: Once a Showdown is initiated, you cannot use standard move anymore until the showdown concludes, so you cannot bring up additional units from your bench during the Showdown.

Sequence:

• Multiple units can be moved to the same destination using standard move
• If you did not control the battlefield, a Showdown is initiated
• From that point, standard move cannot be used until the Showdown concludes
• When a player puts something on the chain (like a reaction), every player has a chance to react unless specified otherwise