How would this work? One of my character ideas is (some undecided stuff)
Thief who killed an innocent woman in a robbery gone bad
Corrupt guard ordered to kill an innocent woman to cover a crime up
Mercenary who killed a young woman by accident in crossfire
Executioner ordered to put falsely accused woman to death
Regardless of choice character is jailed/punishes self before bonding with her spirit as a Spiritualist. His goal is to revive her to atone (and adventure in the name of good in the meantime to build funds).
Assuming he succeeds at his goal how would that work? As a slight aside what emotional focus would be a good fit given her innocence and unjust death across all options?
I guess you could retrain into an archetype that radically alters the phantom in some way. Suitable choices from Occult Adventures would be the Fractured Mind or the Geist Channeler. For the Fractured Mind, the Spiritualist could not handle losing his Phantom companion and thus generates a new one from his own mind. For the Geist Channeler, the Phantom loses most of its personality and memories as the person who was its source is pulled back into the world of the living.
Maybe Occult Origins will offer better options?
That could work. His spirit is bound to him through hatred even as he tries to revive her. When he succeeds he finds he had fallen in live with her and the loss of the closeness and bond makes hm a fractured mind of despair.
I don't think you CAN resurrect a person who has become a phantom. They're not a ghost, nor even an undead at all: the phantom is an outsider "summoned" from the Ethereal Plane. I think that implies that bonding with the Spiritualist changes the nature of their existence. Your idea is an interesting one, but I don't think the nature of the Spiritualist works with it. You COULD do it with a Medium, though.
However, taking it in a slightly different direction, what you COULD do is have the character become an Onmyoji-archetype Spiritualist in order to deliberately call and bond with that specific spirit instead of leaving it up to serendipity, not even knowing whether or not he could ever revive her. You could easily reflavour the holy symbol to be anything, even perhaps something important to the deceased woman, instead of an ofuda, and (thematically) flavour the whole thing aa a cross between Spiritualist and Medium.
If this were to hapen in my playing group, this is how I'd do it:
Spiritualist up to level 6 (play as normal)
At level 7, (or later if you want), you manage to revive her. (or insert her spirit in a "clone"?) You are allowed the leadership feat, gain her as a cohort (if she didn't have PC class levels before, maybe her time as a phantom gave her adivinatory powers or something like that), and retrain your class to something else.
Summoner might work as a new class, keeping with the theme of "contacting strange entities", medium if you go for "now he uses his (half) empty soul to help all spirits", or realy any class you want and justify, taking into account that the ability scores shold remain the same.