On chapter 16, the one where you regain Lyn's castle you can get Raven the mercenary and also have the monk Lucius rejoin your party. To do this bring Pricilla in the battle. Protect her until she reaches her long lost brother Raymond (Raven). Hopefully you do this before the soliders escape or they might hurt him. Let Pricilla talk to raven and get him on your team. Then let Raven talk to Lucius. They are great characters to add to the team.