I do not understand this card. (After attached character's character or upgrade dice deal damage, you may exhaust this upgrade to turn a die to a side showing a blank.)

After I attack with my die and make a damage (into shield or character) I may exhaust this upgrade to turn this die to a side showing blank? Or should I turn another mine die? Or should I turn any other die (including opponents die)?

Thank you for help.

Piece out the statement. First act- Deal damage with attached characters die(character or upgrade), after damage dealt regardless of absorbed by shields or damage to a character. After that is done you exhaust the upgrade to turn "A" die which is any die still in the die pool. Basically you use that to blank an opponents die.