I want to train a team for (Time Attack) Steel Soul, but all my characters except Handles and The Sixth Doctor are level 3. Where should I go?

TEAM - The Sixth Doctor -MAX

           Amy Pond + - Lv. 3

           Handles - Lv. 11

           Jimmy Wicks Ganger - Lv. 3

           Silent Priest (Blue) - Lv. 3

            River Song + - Lv. 3