All the departed souls were pressed into the light curtain of the small space-time ring by the Star Beast Ghost Messenger.
The moment they entered, the space-time ring recorded the information of the soul.
Wang Sheng stood by, watching each piece of information being recorded.
Finally, he thought for a moment and conjured a thick book.
"These souls may enter the Underworld in the future, so letās record them, and also capture the essenceās aura..."
Wang Sheng had seen during the rebirth testing that after reincarnation, the external soul aura changes, equivalent to a new entity.
This is the case even if memory is preserved during reincarnation; the soul aura from the previous life isnāt retained.
But the change in the surface soul aura doesnāt mean the essenceās aura will change.
Therefore, record the essenceās aura directly.
"With the capabilities of the space-time ring, tracing back to the soulās origin is difficult, I still need to assist."
The space-time ring can reverse time, affecting even Twelve Realm Saint Emperors and is used by the Shattered Star Sacred Land as an Oath Secret Treasure that can constrain a Saint Emperor.
However, wanting to trace countless souls back to their essence period is still somewhat challenging.
After all, as an Oath Secret Treasure, it is effective only when the Saint Emperor willingly allows themselves to be constrained.
If the Saint Emperor doesnāt willingly allow limits, the effect is greatly diminished.
But he is different.
His power is such that even if a Saint Emperor actively resists, it wouldnāt change the result.
Therefore, to perfectly record the essenceās aura with the space-time ring, further enhancement from him is needed.
"Since thatās the case..."
Wang Sheng looked at the book he had just conjured.
It was initially intended as a record, but now it could supplement the space-time ring.
So, he directly infused it with the Power of Time, covering the plain book, enhancing it with the power of time.
Then he took out a die.
The Time Dice!
Once obtained as a Starry Sky Secret Treasure on the Heavenly Saint Star, also related to time.
Any Starry Sky Secret Treasure, regardless of its power, is highly unique.
The Time Dice is a Secret Treasure tied with time, its ability being extremely formidable.
Itās just that, due to Wang Sheng bearing the Space-time Dao, his Space-Time Ability was greatly enhanced.
What the Time Dice could do, he could do, and what the Time Dice couldnāt do, he could also achieve.
Thus it ended up gathering dust.
Now it finally has a use.
"Using it as the core of the Underworld Secret Treasure doesnāt disgrace you."
Looking at the Time Dice, Wang Sheng began the refinement process.
The refinement had a high number of breakthroughs, enabling many things.
Imbuing the book with the essence of the Time Dice wasnāt difficult.
Soon, the previously plain book radiated the Power of Time.
Wang Sheng also began adjusting the overall capability.
"First is the recording capability, this book must record the essence aura of countless living beings, so it canāt just capture a small bit of information. It needs to record countless ones, expand using spatial techniques, and requires replication abilities for judges to consult easily."
The original intent of making this book was to enable Underworld officials to consult it easily, especially judges, needing information to judge fairly.
These functions, though not complex, were quickly refined by Wang Sheng.
"The information recording needs to connect with the space-time ring, and that is not difficult. Additionally, while connecting, the book also needs to enhance the space-time ring..."
This function was relatively complex, taking some thought from him.
The main task was coordinating the two Secret Treasures.
Of course, he succeeded in the end.
"Completed. Recording, replication, and enhancing the space-time ring; these functions should suffice. Letās test it."
Wang Sheng threw the book toward the gloomy sky of the Underworld; with an invisible fluctuation, the book disappeared and reappeared, already within the core of the space-time ring.
With a wave, the space-time ring and book emitted the same fluctuations.
Before long, the two Secret Treasures connected.
The book floated directly at the center of the book.
The aura of the space-time ring was visibly strengthened, and the small space-time ringās aura was also enhanced.
Of course, neither the Star Beasts nor the ghosts in the Underworld noticed this change.
Indeed, the change in the space-time ring was significant.
Each soul passing through the light curtain of the small space-time ring would have their time instantly reversed.
Though the effect didnāt apply to the souls themselves, just recording was sufficient.
With the reversal, the book instantly recorded the essence aura of the soul.
Wang Sheng examined the records, and when he tested it with his own time ability, he found no issues.
"Now thereās no problem."
The ability to record the most essential information means that once they come to the Underworld, they are under control.
"This is also a kind of causality... Recording the essence aura means that upon death, a Soul Purifying Sea nearby isnāt necessarily needed."
Recording the essence aura indeed forms a powerful causality.
Should Wang Sheng use it, he could control the soul across endless space-time.
Summoning it back wouldnāt be difficult.
Of course, his current mastery of cause and effect ability isnāt as strong as the power of space-time.
Achieving it on a large scale is still challenging.
"This ability could be used to further enhance the Underworldās functions in the future, but for now, it will be put aside temporarily." Unable to utilize it, Wang Sheng doesnāt mind, since the main purpose is for the judges.
"Since itās already completed, it should have a name. The Book of Life and Death would be unsuitable, the gap too wide, like the difference between clouds and mud... However, it can record and connect with the space-time ring, it can observe past and present lives, so weāll call it the Three-Life Book!"