After Rai kills Roctis, the 5th Elder marvels at his powers while Frankenstein worries for his master's health. Rai checks on the children (Rael, Regis and Seira ) and is relieved to learn that their lives are not in danger. Ignes decides to escape the scene to test out her new soul weapon. But before she does this, she decides to awaken Muzaka so that he may attack (and kill) Rai to avenge her father's death. Muzaka wakes up and, due to a headache, gives out a scream which destroys the lab. From the aura given off, Rai instantly learns that Muzaka is nearby. Rai prepares for battle and tells Frankenstein to evacuate the scene immediately when Muzaka reveals himself out of the dust cloud.
As Muzaka steps out of the dust cloud, everyone appears shocked. Through the conversation between Kentas and the 5th Elder, it is revealed that Muzaka is the previous Lord of the werewolves, who betrayed their kind. Frankenstein also reveals that Muzaka was Rai's only friend, the one responsible for his long hibernation.
Muzaka mutters Rai's name and the two greet each other. Muzaka then convulses in pain due to another intense headache and then transforms, giving off a vast amount of aura. Rai creates an aura force field around himself, blocking the overwhelming release of energy. Rai summons his Blood Demon form, preparing for yet another difficult battle.
Muzaka slashes with his claws towards Rai at a blistering speed, creating an aura infused kinetic shock wave. Rai blocks the attack, but with obvious difficulty, due to his poor physical condition. Although the initial part of the attack was blocked, the pure force from Muzaka's aura-infused claws cleaved a large mountain in half and obliterated an entire forest, causing earthquakes throughout the island.
Muzaka then swings his arm to send a massive energy wave towards Rai, who blocks the attack which destroys the mountain. Rai calls for Muzaka, who is unable to reply, caught in madness and partly unconscious, and then decides to summon a blood field so that he can control and communicate with him. After some conversation, Muzaka screams in pain due to further headaches and the aura radiated dissipates the blood field. Muzaka then sends another huge energy wave, this time towards Frankenstein and Rajak but Rai intervenes to block the attack and saves the duo. After stopping Frankenstein from joining the battle and evacuating them, Rai is faced with another gigantic energy wave from Muzaka, who is enraged at Rai for stopping him yet again. Rai blocks the attack with his palm and then releases his full power, breaking the Ring in the process.
After the dust cloud clears, the two are facing off. Then Muzaka groans in pain and ire whilst Rai starts to bleed from everywhere (including his ears) and the two charge at each other with all their aura gathered around them. Frankenstein pleads for them to stop and the gigantic clash destroys the surroundings. The two separate and continue to smash into one another, neither of them able to dominate fully. Rai's aura is now much more transparent and pure and so is Muzaka's. Then they split from each other. Frankenstein begs for his master to stop the fight and Muzaka screams at him, telling him to back away and stop restraining him whilst slashing the air to send massive energy waves at Rai, who manages to fly away from them. Rai then shoots a huge red energy beam, which surprises Muzaka. He groans in pain and takes the hit directly on, yet he comes out unscathed. He shouts at Rai, asking when he will stop restraining him and rebukes him for thinking and if he really believes that the humans will be grateful. He claims that Rai stopping him won't matter as he will still destroy mankind. Rai tries to gather up strength but he flinches in pain and coughs blood. Muzaka takes the chance and slashes him in a cross and Rai just manages to reach his hand out to block the waves. Then Muzaka sends even more waves spinning around and Rai is severely wounded, unable to block the attack. The Blood Demon form disappears and he stands, groaning in pain. Muzaka charges at Rai, announcing his end and Rai also charges at him, and the two crash into each other. Rai's red aura engulfs the explosion, hence Rai is seen barely standing after the explosion, victorious from the battle.
Frankenstein and Rajak both rush to Rai's side and ask him whether he is alright. Frankenstein reveals that he cannot let the situation continue and that he will do the rest that needs to be done. However, Rai tells him that there is no need for it as he cannot sense Muzaka's aura any longer, probably because Muzaka is also severely injured and won't be able to move for a long time. Rai asks how the children are faring and after hearing a positive response, he coughs more blood, worrying Frankenstein, and looks up at the sky as he groans in pain.