Mecha Giant Beast Megarion (メカ怪獣メガリオン Mekakaijū Megarion?, 47, 49): a mole-like monster with drill arms,

it is deployed by Daruga to destroy the city in a plan to depose of Riceross and its support mecha retreating after he adsorbs the riser power and becomes Kurogane. Later deployed as a distraction while Kurogane summons the Diglos, Megarion proceeds to destroy the city as Gant and Kageri try to stop it on their own before it attempts to kill Mio. However, Ryuto intervenes as Demon Knight arrives in the rebuilt Riseross. Once formed, JustiKaizer easily over powers the monster and destroys Megarion for good.