I had the craziest idea last night (lucid dreaming):
What if someone somehow made a Maria android using her actually brain data (thoughts, emotions, memories, etc) and Shadow has to deal with the ghosts of his past? Knowing she's "fake" but she feels and thinks exactly like her (including loving him)... When he finally moved on? Would he be able to destroy her, facing her terrified face?
I dunno, I love the angst