I can say that seduction and befriending her isn't going to work (part of the problem with Jovavich: she's a shut in with very few friends because she's wanted to fix the colonies system), but it's possible that Cheris could observe her! Stalking her, tracking her behavior and haunts, with Akechi providing what detail he has for when she can take over from when he's at work. He'd have to hold on to his job for longer, but it could give them either an opening to the Johann dealio or a means to let Akechi use his power on her unobserved.