Despair at the Diverging Past and Causality

Tokiya has managed to open the gate to the Third World and the Second World has begun to vanish at an alarming rate. As such Tomo and the others must gain access to the Central Vortex in order to confront Tokiya and save the world. However, with Tokiya in control of not only Hagane but Hisui, Bismuth and Rhodonite as well that may not be as easy as it sounds.