Ken found his way into the dungeon, took down the guards(without violence), and located the prisoners. Unfortunately, to free them, Ken need to take down the castle's last ditch of defense-- a giant sentient toy casted with spells for eradication purpose.
The Quadroid, as the Darkners calls it, similar to Lawrence's Penta-Tron, is protected by magical spells, rendering physical attack useless. Ken will have to rely on his magical weapons to take it down.