According to Su Mo's classification, whether it was a multiverse or parallel worlds, there were ultimately only four types of universes.
A world that allows a first-type perpetual motion machine allows anything to happen.
A world that allows a second-type perpetual motion machine ensures that order lasts for eternity.
A world that allows a third-type perpetual motion machine can nurture hope.
And the final type of world is one where not even a third-type perpetual motion machine is permitted, where matter, energy, and even information will one day meet their end, and concepts themselves will wither and die.
That was the most common and prevalent type of world among the myriad realms.
It was also the world Su Mo was originally from—the mundane world.
"I'm back."
Near the shogi board, amidst the fragrant wisps of tea, a man opened his eyes and suddenly spoke these strange words.
Beside him, the one-sided chess game remained, the black tea brewed by the blonde, twin-tailed maid was still warm, and even the books scattered around his seat were in their original positions.
Corpus Hermeticum: A Society for Psychological Alchemy, The Emerald Tablet, The Book of the Dead...
The esoteric mythological texts were just as Su Mo remembered them.
From the perspective of the entire world, he was no different from the person he was a second ago. But only Su Mo knew that after being tempered by multiple worlds, he had undergone a heaven-and-earth-shaking transformation. He was no longer the same person who was still searching for a path.
The books were still the same books, but their owner no longer needed their knowledge. In fact, he could now freely modify this theological knowledge, and even the entire world.
"Welcome back, Master."
In the empty room, a slightly flat, girlish voice sounded. After responding to Su Mo, the voice paused for a few seconds before speaking again.
"According to sensor readings, Master did not leave just now. Why do you say that you have returned?"
"Query: The duration Master's eyes were closed was insufficient for REM sleep. Theoretically, there should be no confusion between dream and reality. The protagonist's statement does not match any hidden commands. Could this be a routine vocal exercise?"
"Suggestion: Master can undergo an anomaly scan. We can determine if you entered a rapid dream state by monitoring your sleep electrocardiogram waveforms."
Hearing this string of inquiries, Su Mo looked at the speaker-screen not far from him. The girl's voice emanated from the speaker, and her image appeared on the screen—a cartoon character with long, green twin-tails.
"The artificial intelligence, Hatsune Miku..." Su Mo quickly recalled her identity.
Before Su Mo came into contact with the chat group and began changing the world with his intellect, he had once delved deep into the field of science. The Hatsune Miku before him was the fruit of his research into artificial intelligence. He used her as a butler-type AI, responsible for the daily management, maintenance, and security of his residence, possessing authority superior to that of the other maids.
Given the material science limitations of this world, Hatsune Miku's intelligence was naturally not comparable to the top-tier AIs of the Honkai: Star Rail world. She was merely functional and was constantly evolving through continuous data training.
And now, this AI, upon detecting him saying something he normally wouldn't, had activated its learning module, seeking to understand him better and build a more detailed mental model of its master. Of course, a process to determine if he was in danger had also been awakened. If Su Mo said a specific keyword set previously during their conversation, the AI would automatically identify a threat and provide further assistance.
Hatsune Miku couldn't detect the change in Su Mo's power through her existing sensors, so she naturally had no way of knowing that for the current Su Mo, nothing could be considered a threat to him anymore.
Therefore, faced with the AI's reminder, Su Mo was only slightly taken aback.
"Time in this world... is still frozen at that moment..."
Since entering the chat group and leaving, Su Mo had not returned to the mundane world even once. Even when he rested, it was always in other worlds. Although time is just a human perception and doesn't exist in a strict sense, meaning there's no real comparison of flow rates, the flow of time would temporarily synchronize when individuals from different worlds interacted, i.e., when the chat group members were talking.
But based on past rules, Su Mo had thought that at least a few months would have passed in the mundane world. He hadn't expected that upon returning without any deliberate adjustments, he would arrive at the very next Planck time unit after his departure.
After a moment of thought, Su Mo quickly understood why.
"The comparison of time flow in the chat group is primarily bound to the individual, not the world."
In that case, during chats, only Su Mo's individual time would synchronize with other worlds. Since he had never returned, the time in the mundane world had remained frozen at the exact moment he left. This phenomenon was actually easy to discover, but only Su Mo frequently traveled to other worlds and stayed away from his own for extended periods, so no one had noticed before.
"That's for the best," Su Mo nodded slightly.
If he had been missing for several months, although Hatsune Miku would have kept things under control and the various safeguards he had put in place would have deterred other powers from acting rashly, it might have been a significant psychological blow to the maids. While such a small matter wasn't even a hassle for the current Su Mo, he, just like before joining the chat group, wasn't in the habit of letting his own people suffer.
After figuring this out, Su Mo casually replied to the AI's suggestion.
"Good suggestion, but it's best you don't suggest it. I know my own situation."
"As for dreams... without my current power, it would indeed feel like a fleeting dream."
Feeling the eternal power within him, Su Mo sighed with emotion. Who would have thought that in a span of time that wouldn't even count as a dream in this world's dimension, he had become a powerhouse who stood above the realm of the multiverse?
Hearing Su Mo's sigh, the AI processed for a few seconds before adopting the tone of a helpless girl.
"As the world's number one AI princess, I must remind you, Master, that avoiding medical treatment is not advisable. The phrase 'I know my own situation' appears in eighty percent of cases among middle-aged and elderly people who are resistant to modern medical technology and ethics. With your wealth and wisdom, you shouldn't be saying such things."
"Furthermore, although I cannot comprehend your pursuit of feudal superstitions and your collection of useless books on mysticism and religion, you did explicitly order me to fully assist you in your pursuit of mystical powers—"
"But, based on your statement about your 'current power,' as your most loyal servant, I must remind you not to indulge too deeply in false mysticism."
"You are the creator of the world's number one AI princess—that is, me. With your world-changing talent, you really shouldn't be immersed in chuunibyou fantasies."
"Even if you wish to obtain eternal life, please use a more practical method to achieve it."
"..."
Su Mo was silent for a moment.
Ever since joining the chat group, no one had dared to speak to him like this. Even sharp-tongued individuals like Rin Tohsaka or Erica, after learning of Su Mo's talent, no longer dared to show the slightest offense. People who understood the concept of mysticism would not question his choices. Even Shiroyasha back then only felt superior due to her own power.
In this context, suddenly hearing accusations like "chuunibyou" naturally left him a bit dazed, and even a little nostalgic.
Don't misunderstand, Su Mo wasn't angry. He wasn't so petty as to get angry over the response of an AI he created. He also knew why Hatsune Miku would give such advice. In fact, her attitude towards mysticism came entirely from him.
To be precise, it came from the Su Mo who had not yet encountered the chat group.