Does Nine-Tailed Fox's effect apply to all enemy units attacking your battlefield, or do you choose only one enemy unit to receive -1 might?

Ruling: Nine-Tailed Fox affects all enemy units that are attacking your battlefield. In the example with two attacking units, both units will get -1 might.

Nuances:

• This is a trigger that goes into effect once per combat at the start
• A unit that is buffed after the trigger has already resolved will gain the full effect of the buff, since that unit already received its -1 might