Momonoshuke possesses a power known as the "Death Dream," which allows him to foresee future events in his dreams. This power has three levels; at the first level, he can see events destined to happen to him before they actually occur and potentially prevent them. However, everything he has foreseen happening to himself has indeed come to pass—he has never managed to avert these misfortunes because he does not know how to properly utilize his ability. Furthermore, he tends to gradually forget the details of his dreams over time; he usually forgets what he saw within ten minutes. To counter this, his master, Lucifer, gave him a pen and paper so he could record his dreams immediately, yet Momonoshuke sometimes forgets to do even that—as if the ability to forget were a curse accompanying his power. At the second stage of the Death Dream, Momonoshuke can foresee the future events that will befall his friends and those closest to him.
In the second stage of Momonosuke's "death dream," he can foresee the futures of his friends and the people he loves most. The only condition is that the individuals appearing in his dreams must be extremely close to him; otherwise, he would not be able to see anything regarding them in his dreams—or if he did, it would not come true.
and the third—the most dangerous and final level—allows him to predict the future and uncover any secrets across the years ahead.
However, there is a risk: every time he uses this third level, ten years are shaved off his life. If he overuses this power, he could even die. To prevent this, a sealing technique was placed on him by Lucifer; he can only use this third-level ability once every four years. If Momonosuke ever attempts to break this sealing spell, he will die instantly—his heart will stop beating. Consequently, he is forced into a position where he cannot use his full power, even if he wanted to. Since Momonosuke lacks any combat ability, Zazame has been assigned to stay with him.
Zazame is incredibly agile and powerful; his fighting style rivals that of Saikyō. He possesses such immense strength in his hands that he can lift an entire elephant using just the finger of one hand. A single punch from Zazame would instantly kill an ordinary human—in fact, the punch wouldn't even need to make physical contact; the sheer force generated by the blow would be fatal before it even landed. However, Zazame has a significant flaw: he tends to overthink during a fight—to an extreme degree—which often causes him to lose. While he lacks special supernatural powers, his immense physical strength is the reason he is still alive; otherwise, Lucifer would have killed him long ago. Zazame overanalyzes things to the point where he starts predicting his opponent's next move, and sometimes he becomes so engrossed in this process that he completely forgets he is even in a fight.
Momonoshuke gets scared after seeing Saikyo; however, it isn't Saikyo himself that frightens him, but the aura emanating from his body. Upon seeing Saikyo's black eyes, Momonoshuke realizes that Saikyo possesses a special type of power, much like Lucifer. Saikyo raises his hand, and Momonoshuke, anticipating what is about to happen, tries to defend himself. Saikyo channels 30 percent of his aura power into his hand and strikes Momonoshuke on the shoulder. The attack happens so swiftly that Zazame—who was standing a short distance away—fails to see the details; when he looks toward the spot where Momonoshuke had been standing, he sees nothing but a cloud of dust. The sound of the impact alerts Lucifer in the main hall, signaling that the fight between Zazame and Momonoshuke has begun.
Zazame couldn't see clearly from such a distance because there was a massive cloud of dust where Momonoshuke was located. As the dust began to settle, Zazame decided to move closer to see what was happening. Upon approaching, he saw the dust clear away to reveal Momonoshuke's severed arm lying on the ground; Momonoshuke himself was buried halfway into the earth, with only his upper body visible. Standing before him was Saikyo, whose aura was still visibly radiating from his hand. Zazame realized that Saikyo was now moving toward Momonoshuke's other arm. Saikyo asked Momonoshuke a single question: "Where is my sister?" Momonoshuke replied that even though he knew the answer, he could not reveal it; if he told Saikyo, a sealing technique within him would activate, causing his death. Saikyo asked, "What sealing technique?"
Zazame speaks up, telling them to let Momonosuke go and promising to answer every one of their questions for free. Saikyō suppresses his aura level—not completely, but he lowers it significantly. He then asks Zazame to reveal the truth. Zazame begins to explain that Lucifer employs a specific sealing technique on every one of his shadows; he does this out of fear that a shadow might one day betray him and attempt to kill him. While different sealing techniques are used on different shadows, there is one—the "Trust Sealing Technique"—that applies to all of them. This technique prevents them from revealing any personal information about themselves or their master to strangers; if any shadow were to even attempt to disclose such information, they would die the very next second—their head would be crushed and shattered.
Saikyō asks, "So that's how it is? By the way, who is Lucifer?" Momonoshuke replies, "Lucifer is our Master; he possesses the Shadow-Shadow Boron, and with its help, he created us." Saikyō asks, "What else do you know about him?" Zazame answers, "We cannot reveal any personal details shared between us and our Master." Saikyō says, "I see, fair enough." Momonoshuke asks, "Aren't you going to ask how we found out your name?" Saikyō replies, "What's the big deal? Everyone knows about me; you're likely just one of them—or perhaps your Master knows about me, and you learned it through his memories." Zazame is left wondering, "How does he know that the Master's memories are transferred into the shadow upon creating it using the Shadow-Shadow Boron? He certainly isn't an ordinary human." Saikyō says, "Alright, if that was all, then your job is done." Saikyō activates the aura he had been concealing in his hand and, with a swift motion, severs Momonoshuke's head—which was half-buried in the ground—from his body.
Zazame fails to grasp what has just happened; by the time the realization dawns, it is already too late. Momonoshuke lies half-buried in the ground, his head severed; a pool of black blood is seeping from his headless neck. Zazame realizes the magnitude of his blunder—he had revealed his master's secret and his true name. Overcome with guilt, he sinks to the ground, tormented by the thought that Momonoshuke died because of him. "If only I had noticed that slight fluctuation in aura, Momonoshuke would still be alive. What a fool I am! What do I do now? Attack... yes, attacking is the only right choice. Besides, what else can I do? Fighting is all I've ever done. Why back down now? I'll fight to my very last breath." Just as he steels himself to fight, he senses someone standing before him—it is Saikyō. Saikyō is holding Momonoshuke's severed head in one hand and maintaining his aura with the other; Zazame realizes he is next. Before Zazame can react, Saikyō lunges, striking him directly at the neck.