A Brief Summary Of My Basic Question Regarding The Christ Myth Theory

The Christ Myth Theory argues Jesus was never on earth, but was originally seen as a celestial being crucified by sky demons in outer space.  Parables that placed Jesus on earth were written later.  Jesus was a one time blood magic sacrifice, infinitely greater than the blood of animals, that appease God’s holy wrath and atoned for sin once and for all.  My response is that the most basic meaning of the cross is that we come to see ourselves in the disciples who abandoned Jesus and those who wrongfully brought about his death, and so this brings about guilt inspired repentance and transformation.  This makes perfect sense if Jesus was a beloved cult leader who was seen as wrongfully tortured and killed, but falls apart on the mythicist reading because how does a celestial Jesus who was never on earth and crucified by sky demons serve as a catalyst for transforming an evil conscience into a good and holy one?