if a blood hunter drop to zero hp when they have a crimson rite active does the crimson rite fade and restore them to consciousness? You do not regain hit points when you lose the rite, just the Max HP. You would remain unconscious.
— Matthew Mercer (@matthewmercer) January 14, 2018
You can download Blood Hunter class here:
http://www.dmsguild.com/Blood-Hunter-Class