"If I fused with the Serene Gem, I should be able to become the Herrscher of Death—or rather, a pseudo-Herrscher of Death. I remember that when Mei later became the Herrscher of Thunder, she formed a new Conquest Gem inside her body, causing the Conquest Gem inside Kiana to disappear. That was what saved Kiana at the time. If I took this Herrscher Gem out of this world, would Honkai create another Serene Gem?"
After studying the Serene Gem for a while, Shen Fei discovered that unless he fused it into his body, further research would be quite difficult. Mainly because he did not possess the technology to create Keys of God.
"Looks like I really need to make a trip to the Elysian Realm. Some technologies only existed in the Previous Civilization." After realizing he could not continue his research, Shen Fei temporarily put aside the Serene Gem and turned to researching the Honkai Neutralizing Serum with Doctor Maki.
It was not as if Shen Fei had never considered fusing the Serene Gem into his body. He could confidently say that he did not care about the corrosion of Honkai energy or the erosion of Honkai consciousness. The reason he was not doing it now was that he wanted to wait until matters concerning the Herrscher of Reason Core had been settled.
As for making Seele the Herrscher of Death, that could wait until later, depending on the circumstances. In any case, the Herrscher Gem could be removed at any time. When the need truly arose, he could simply take out the Serene Gem and give it to Seele.
"Come to think of it, Sirin really was blessed by heaven. Not only did she have multiple Herrscher Cores, she also had the consciousness of Honkai Beasts backing her up.