After reading countless theories I feel that It may be obvious in choosing Brett Partridge but I feel they will add a twist. What if Partridge is a half brother of Janes. Janes father (who we dont hear mentioned enough) could have had another son with similar talents to Janes. The last episode seemed adiment in bringing up Patrick's youth.  Brett seems like a mirror image of Jane and It wouldn't shock me if we start to learn more about Janes' father early next season and it comes to fruition with The Jane family all being involved.