I definitely made the game harder because of the abilities I added to each character. If you use them it can make that fight easier. ( you need to have the characters at level 3). Also , think about the best way to split the team.
The secret character can only be obtained by talking to the priest at the beginning. Talk about the dreams and that will kick off a chain of events.
Talk to priest , then talk to him again after gardenia is destroyed , he will have people with him. You will get an item from one of them and that is used to get the character in Alterone. You get the secret character before the king betrays you, so check everywhere before talking to the king.
The secret town can only be found if you save Khris’s family.
I have never made a game before so I may have not balanced it well. It might be a tad difficult.