Everyone is confused. Focus on their souls? The demon remembers that the humans do not actually know how to even access their soul, and he explains. "Reverse the flow of magic within your bodies. At the end, you'll find the source of your magic; you soul. Once there, focus all of your magic onto it. If done correctly, magic should come out of the middle of your torso."
And so that happens, except for the fact that that's not the case for Akio and Kurayami, though the demon knows the reason why. That is, he only knows it about Kurayami, not Akio. In any case, the session is complete, with Kurayami and Akio being asked to step aside.
The two are asked to burst their souls. Before they can even ask the demon to elaborate, he tells them that "bursting" one's soul is essentially exploding one's magic energy. This should serve to help Kurayami, but Akio was also asked to do it because it's speculated that he, too, can benefit.
Following their instructions, Kurayami attempts to do this "soul burst" (as referred to by Akio) first, seeing little results, though the demon knows that this is helping her. A few minutes later, the demon asks her to stop, seeing that nothing more will come out if Kurayami pushes herself further.
Akio, on the other hand, begins his own soul burst. The demon can't directly see what is happening, but he knows that Akio's soul is starting to change, immediately asking him to stop. After this, Astaroth appears, telling Akio that based on what just happened, he shall be put in a personalized training session that will have the aim of strengthening his soul immensely.
Nodding, the young adult asks Kurayami to go back to the others, as he follows the two demons back into Hell. Satan welcomes the young one once again, informing him of his training. It's something called illusion training, which brings out one's greatest weakness and has the trainee overcome it, possibly evolving themselves in the process.
Satan then goes on to explain that this will greatly benefit Akio, whose soul has a unique attribute. If done correctly, he may even get strength that rivals that of the two deities themselves. Akio understands and asks when will this training begin, eager to get stronger immediately.
The time is not ripe, however, so Akio is asked to prepare himself and return early in the morning, as they'll be ready then. Akio listens to the deity's request, leaving for the night. Meanwhile, Satan and Astaroth discuss about someone.
"Yes, my lord. She is.. the daughter of--"
"My lord, someone's watching us."
Astaroth had started to confirm something important to Satan, but he had noticed a strange presence. It couldn't be Akio, since the magic energy was different, however, this one was dark and unfamiliar. Astaroth chased this energy, only to see that the spy had already left, something which was troublesome for the two, but they decide to simply prepare for tomorrow.
Tomorrow arrives. Akio wakes up at what would be 6 AM in the mortal realm/Earth, as he heads out to Hell, where Satan, Astaroth, Beelzebub, God and Michael awaited his arrival. The young one was confused, but the two deities explained that he'll be under strict surveillance during his training, since he is special.
That, however, simply meant the two deities would remain, alongside Astaroth, as Beelzebub had to tend to the stronger team's training and Michael had to oversee the weaker team, though everyone was oblivious to the fact that they were once again spied upon, but not by the same person as yesterday.
When Beelzebub arrives to the training grounds of the stronger team, he notes that Kurayami is not there, as he starts to worry. Meanwhile, Akio is bound by divine chains, a precaution suggested to him by God, which the young human had consented to.
Soon after, his training begins. Akio falls unconscious and awakens in a strange place, having forgotten the events that transpired ever since he finished his training session yesterday. He sees Kurayami next to him, apparently having awaited for Akio to wake up, and he says that he's ready, as they head towards the light in front of them.
Soon enough, they encounter dark soldiers, which they start to fight. At first glance, it seems as though the couple has the upper hand, but that assumption is soon invalidated. Kurayami is pushed back, while Akio, who had lowered his guard a bit, was thrown away.
They both use "Soul Burst", with Akio also subconsciously activating his cursed form and Burning Sense, though he now notes that his magic energy will not last long. He and Kurayami clean up through the soldiers fairly quickly, since they had no other choice. At this point, they'd normally get a break, as per the plans of God and Satan about this training, but that was not what happened.
In fact, the very opposite happened, with a seemingly bigger soldier appearing in front of the couple. His magic energy signature is so strong, that even the two deities, alongside Astaroth, can feel it from Akio's soul, in which the training had taken place.
Astaroth recognizes this energy to be the one from yesterday, and he notes that Akio is definity in trouble, because even if this is illusion training, that soldier is very real, which can mean harm. The two deities, however, cannot do much other than try to get the soldier outside of Akio's soul.
Meanwhile, inside the latter's soul, he charges in at the soldier alongside Kurayami, both using 100% of their power, though they're almost completely overwhelmed. The soldier crushes Akio, much to Kurayami's disbelief, as in the real world, his actual body starts to tremble, with it losing magic energy, alarming the three.
The soldier reveals himself to be one of The Dark Commanders, calling himself Jett. That will not matter for the two, however, as they will die a dishonorable death, filled with suffering. Jett moves on to Kurayami, but Akio stands in front of him, with an incredibly weakened body, telling him that if he dare lay even one fingertip on her, he shall die.
Jett laughs at this empty threat, simply swatting Akio away. As for Kurayami, he finds her to be 'cute', so he will not torture her as much as he did Akio. Walking closer towards her, Akio becomes increasingly angrier, with this also being portrayed in his real-world body counterpart, which is starting to charge up with magic energy.
God is very much worried, alongside Satan, because they can't find a way to take Jett out of Akio's soul, preparing for the worst, which is about to happen. In front of Akio, Jett is brutally beating up Kurayami, after having decided to actually torture her even more than Akio.
Akio is in a heavily agitated state, currently, but seeing his most important person getting tortured like this in front of him while he's powerless to do anything was the icing of the cake. If only.. if only he had the power to turn the ti-...
Before even being able to finish his thought, Akio is in a state of deep shock, anger, confusion and sadness. Kurayami is sent towards him, as they both crash onto the mountain. As he turns down to look at his lover.
His eyes widen. In Akio's place remains a broken shell, full of anger. He cannot believe his eyes. In his hands, Kurayami lays dying, having a gaping hole through her stomach, with some of her organs actually being visible.
With the last of her stamina, she tries to raise her right hand, trying to embrace Akio, whose face is filled with a mix of anger and sadness, as he holds his beloved in his hands. A tear falls, as Roland appears behind him, choking him tightly, while the latter turns into dark magic energy, entering Akio.
"I'll be the power that you need, but in exchange, you'll give me your body."
His devilish magic energy is so intense that even everyone in the real world can feel it, and the three overseers of Akio know that they must get away now. Jett is forcibly knocked out of Akio's soul, as darkness envelops his real body.
The divine chains break, and Akio's body turns completely black, with him having lost his pupils. With one scream, Satan's Hell Castle is obliterated, with everyone being knocked back. The force can even be felt by Astaroth and Michael, who cannot even move, as they're trembling.
Jett gets up, having been visibly injured by Akio's new apparent transformation, as he tries to rush the young berserker. Akio, in response, charges a shadow beam from his mouth. Upon firing it, it decimates everything in its path, but what has become of Jett..?