2019-05-03 : Casting Blindblast after a creature has blocked won’t remove the blocking creature from combat unless the damage Blindblast deals causes that creature to die. It won’t cause the creature it blocked to become unblocked even if the blocking creature does die.

2019-05-03 : If the target creature is an illegal target by the time Blindblast tries to resolve, the spell doesn’t resolve. You won’t draw a card.