Moonsong could fail, and MC could come across a power that allows the user to disable others' power. or he could find eyes that allow to see the invisible, and he would be the only one able to interact with her normally, adding another reason for her to love him. though the last one would not stop her from getting sent to japan.In Amber's case i was thinking less about death in more about her being forced into doing something she wouldn't normaly do, like in case Moonsong fails to help her but she gets approached by one of the villains who can actually help her. With the prospect of being sent away to Tokyo and her depression getting worse i could see Amber accepting such deal.
But that is just some wild musing of myself.