Raubahn, Bull of Ala Mhigo

• 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].

• WWizards of the Coast2025-06-06
  Official Ruling
  Use Raubahn's power at the time the ward ability resolves to determine how much life must be paid. If Raubahn is no longer on the battlefield at that time, use Raubahn's power as it last existed on the battlefield. (If this matters, you must have a very good reason for wanting to pay life.)
• WWizards of the Coast2025-06-06
  Official Ruling
  If the target Equipment can't legally be attached to the target attacking creature when Raubahn's last ability resolves, the Equipment won't move.

Rulings via Scryfall