Lovelorn characters become love-worn with the passage of time. Deep yearning for connection, any kind of connection, leads people to do terrible things. The connection between any two people can eventually break. Such is the inevitability of life when a relationship moves forward, gets weaker, and cycles back to become stronger. Aging does this quite a bit. Relationships see this happen a lot particularly when there is a theatrical phantom afoot. Whenever a phantom tries to find his meddlesome way into any relationship well things can get a tad complicated with it. No amount of law enforcement can stop it. Rather it takes a more hands on approach to get everything completely accurate.
The phantom is real. People try to not believe it that a phantom would bother with the Paris opera but there he is messing with them. Usually phantoms opt to haunt various families trying to take over an entire home. Haunting commercial real estate generally has little going for it. By haunting commercial real estate there are all these complications. In an opera house that is increased tenfold. Sure perhaps there is an abundance of wonderful seating, great views, comfy chairs, yet it is a bit hollow. People give themselves up for the opera sing their souls out and it hurts to watch at times. For nobody is there to truly understand them. The audience goes home. Their families support them. But for those lonely ones there is the phantom willing to be there for them no matter what.
For a while that obsessive, compulsive attention can be a bit endearing even romantic. The flame that burns brightly can become so easily extinguished. Better to pace. With pace the slow gradual understanding of one another becomes apparent in time. Rushing getting to know one another can result in great disappointment. Insane individuals like to hide behind their passion convincing others that theirs is their art. Ruses like this can be remarkably effective leading the other to avoid the telltale signs that this might not be the best possible idea.
Of course the obsessive compulsive relationships end badly. There is no other way. People from the outside intervene. They see what happens they have agency to make a difference. Maybe the insane artist will never be understood; maybe they will continue to be a phantom finding new haunts. At some point they too find new communities, places to linger where their faces will be unknown and new. And then the cycle will continue.