Shadowspear

• WOTC Official Reminder Textofficial rules
  Equip — Equip [cost] ([cost]: Attach to target creature you control. Equip only as a sorcery.)

• WWizards of the Coast2020-01-24
  Official Ruling
  If a permanent enters the battlefield under an opponent's control with hexproof or indestructible after Shadowspear's second ability resolves, it won't lose that ability unless you activate Shadowspear's second ability again. The same is true if an opponent's permanent gains indestructible or hexproof after Shadowspear's second ability resolves.
• WWizards of the Coast2020-01-24
  Official Ruling
  You can activate Shadowspear's second ability whether or not it's equipped to a creature.
• WWizards of the Coast2020-01-24
  Official Ruling
  Because damage remains marked on a creature until the damage is removed as the turn ends, damage previously dealt to a creature with indestructible may cause it to be destroyed if Shadowspear's second ability resolves during that turn.

Rulings via Scryfall