I always liked the idea of Grimm Pyrrha being Pyrrha only in looks, for the most part. Her attitude would be more of a punk and rebellious. Listens to Salem because she doesnt have a way to get away from her. GP finds Jaune interesting, and constantly forces them to have 1 on 1 duels even if Salem bitches about GP not following the plan. Grimm Pyrrha would do some digging about what human Pyrrha and Jaune's relationship was. Then during their fights, she would start to tell him that she is much better than the old Pyrrha. Loyal, better fighter, alive, sure she has a natural tendency to want to maim and murder, but a fight every so often cools her down. She just needs to break Salem's hold on her. Jaune's aura can because of reasons, and then GP becomes a part of the team.