Since even his Temporal Annihilation fist could not end Wyatt's life, Belphegor knew an ordinary plague would be far from sufficient to kill Wyatt. So regardless of how precious a realm fragment was, he did not hesitate to use it as an ingredient to create a plague potent enough to end a realm's will within moments of it being introduced into the said realm's space.
As such the devil had taken the world's will hostage with his plague egg created from a realm fragment. The world's will was responsible for all life in the world. If the world's will dies all the lives living on it will cease to exist with it. Which included Wyatt.
However, Belphegor was still not assured that this would be enough for him to end Wyatt's life. After all, Wyatt had become a demon merchant using his recommendation. One thing Belphgor knew about demon merchants was that even if their home world was dead they could move to another world making an appropriate sacrifice to the devil merchant code. n0Velusb.c0m
Therefore, he offered Wyatt a deal to save the world by exchanging it for his life. This way he could not only ensure that Wyatt was dead but also taint Wyatt's soul through the plague such that he could drag it to his hell regardless of Wyatt's prior deal with other devils.
This was why he hinted to Wyatt that he could always move to another planet when he was no longer able to hold the plague in. he did not care about the card world he only cared about securing Wyatt's soul. Fight him, Belphegor realized Wyatt's soul had far greater value than he previously deemed it to be. The secret to Wyatt's time immunity alone suppressed the value of the realm fragment he used to create the plague.
All while acting as if Wyatt had a say in this, Belphegor was forcing Wyatt to implant the plague in his body by persuading him that it would be the best possible outcome in hopes that Wyatt was righteous and loyal enough to sacrifice his life for his world.
"Realm fragment," Wyatt muttered not paying attention to what Belphergor or Colleen were saying to persuade him to do what they felt he should do.
Realm fragment as the name suggested was the fragment of a realm's will. There was only one way to get a realm fragment and that was by destroying a realm not just in the physical plane but also its will in the spiritual plane. Realm's Will was like the root of a weed, even if their physical form in the physical plane was destroyed with time they could revive and repopulate the realm. But once the realm's will was destroyed there was no way to revive a realm.
The realm fragments were remains of their realm's will and rules, devils refine them to pave their way to the transcendence. This was why power devils went out of their way to conquer countless realms. As for weaker devils, they formed groups to conquer and the realm slowly accumulated power until they were powerful enough to conquer and occupy a realm by themselves.
However, refining a realm fragment was easier said than done. As it was not easy to subdue the remanent of the realm's will in the realm fragment not to mention the remains of rules in the realm fragment were different from the rules of their native realm. From subduing the remanent realm's will to aligning the rules of the other to that of their realm, it was a lot of work even for a devil. However, nobody said that the path to transcendence would be easy and smooth.
Despite its priceless nature, Wyatt believed if it was to kill him, it was possible for the devil to use such a valuable ingredient to create a plague powerful enough to kill him. The grudge Belphegor held against Wyatt had already progressed to the point where the devil was willing to give an arm or leg to kill Wyatt. Let alone his Worldhog incarnation and a realm fragment.
Considering the calculative nature of the devil, it must have already determined Wyatt's soul's value to be greater than the combined value of a Worldhog incarnation and a realm fragment for it to proceed with such a plan without hesitation.
So Wyatt did not that the devil would be willing to use a realm fragment to kill him. As for whether it had a realm fragment, to begin with, the devil was a devil merchant who conquered countless realms, for him producing a realm fragment was not a big deal but not cheap either. It must be a big percentage of its wealth. After all, not all realms were strong enough to leave behind remnant wills. Therefore, forcing the devils to cultivate the conquered realm to their maturity.
"You are lying, realm fragments are not easy to get," Colleen argued
"What do you hillbillies know about realm fragments? Have ever seen a true realm fragment? I will have you know those measly remains that you get as a reward after you clear SSS-rank dungeons cannot be considered realm fragments. You will have to collect thousands of those for them to amount to a realm fragment. But it is commendable that a few of you have used it to find your path to transcendence, admirable indeed. Unfortunately, you were born in the wrong realm," Belphegor looked at Colleen with pity. With her strength to break into his secondary time flow, he had come to acknowledge her.
Though Wyatt was hard to kill like a cockroach, she was actually giving him a sense of threat. If not for her Cyrosynthesis still being underdeveloped she would have been a formidable opponent to fight against. Which was why he even bothered to engage in an argument with her. As they argued the rhythmic pulsing of the plague egg grew faster signaling it that it was going to hatch any second now. Belphegor grew impatient wondering what was taking Wyatt so long to reach a decision but to not seem desperate he masked his desperation with his argument with Colleen.
"I will take it," Wyatt uttered loudly gaining the attention of both Belphegor and Colleen.
"No, you can't." Colleen immediately opposed Wyatt's choice
"You sure?" Belphegor asked Wyatt playfully getting his way.
"Yes, I am."
Colleen stared at Wyatt in disbelief, she could not believe he was willing to sacrifice himself for the world. But remembering that this young man wagered his soul with the devil to save her granddaughter she thought, it's just like him to step up when needed.