Righteousness

• WWizards of the Coast2009-10-01
  Official Ruling
  A “blocking creature” is one that has been declared as a blocker this combat, or one that was put onto the battlefield blocking this combat. Unless that creature leaves combat, it continues to be a blocking creature through the end of combat step, even if the creature or creatures it was blocking are no longer on the battlefield or have otherwise left combat.

Rulings via Scryfall