Avacyn, Angel of Hope

• WOTC Official Reminder Textofficial rules
  Indestructible — Effects that say "destroy" don't destroy this permanent. A creature with indestructible can't be destroyed by damage.
• WOTC Official Reminder Textofficial rules
  Vigilance — Attacking doesn't cause this creature to tap.

• WWizards of the Coast2020-08-07
  Official Ruling
  Because damage remains marked on a creature until the damage is removed as the turn ends, nonlethal damage dealt to a creature you control may become lethal if Avacyn leaves the battlefield during that turn.
• WWizards of the Coast2020-08-07
  Official Ruling
  A planeswalker with indestructible still loses loyalty as it's dealt damage. It is put into its owner's graveyard if its loyalty becomes 0.
• WWizards of the Coast2023-07-28
  Official Ruling
  A battle with indestructible still loses defense counters as it's dealt damage. If it's a Siege, it will still be exiled when the last defense counter is removed from it, and its controller may still cast it transformed without paying its mana cost.

Rulings via Scryfall