Use the following trick to restore HP and PP free in your first visit in Kibombo before solving the orb problem, When you first find Piers in Kibombo, train your party at Kibombo Statue. After some battles, you will need health and PP. Get out of the statue and go west of Kibombo. Get the Magic Stone to restore PP then with Piers with his attack Ply or Plywell. It will restore HP. Then, go south of Kibombo and Piers will leave your party. Go back to him and he will fully healed by himself.