Bronze Guardian

• WOTC Official Reminder Textofficial rules
  Ward — Whenever this permanent becomes the target of a spell or ability an opponent controls, counter it unless that player pays [cost].
• WOTC Official Reminder Textofficial rules
  Double strike — This creature deals both first strike and regular combat damage.

• WWizards of the Coast2021-04-16
  Official Ruling
  The ability that defines Bronze Guardian's power applies in all zones, not only while it is on the battlefield.
• WWizards of the Coast2021-04-16
  Official Ruling
  Once a ward ability has triggered, it doesn't matter if the artifact loses ward (most likely because Bronze Guardian leaves the battlefield in response) before the ability resolves. The controller of the spell or ability will still have to pay or the spell or ability will be countered.

Rulings via Scryfall