Hollowhenge Spirit

• WOTC Official Reminder Textofficial rules
  Flash — You may cast this spell any time you could cast an instant.

• WWizards of the Coast2011-01-22
  Official Ruling
  If there are multiple combat phases in a turn, a creature that’s been removed from combat can still attack or block in future combat phases that turn.
• WWizards of the Coast2011-01-22
  Official Ruling
  Removing a blocking creature from combat doesn’t cause the creature it was blocking to become unblocked. If no other creatures are blocking that attacking creature, it won’t assign combat damage (unless it has trample).
• WWizards of the Coast2011-01-22
  Official Ruling
  Removing an attacking creature from combat doesn’t untap that creature.

Rulings via Scryfall