Rei made a few more tests like having Solution kill a low-level treant he summoned, asking her if she got experience from it. Apparently, even NPCs could level up and breach the level cap since she was also level 100 with a full exp bar prior to that test.
After that, Rei tried a different approach and started using items that summoned pop monsters like Horn of the Goblin General and the like.
Seeing a real goblin being spawned and almost shit himself as he spotted Rei was amusing. Using a second-tier Lightning Arrow spell to kill it and witness the momentary look of horror on the creature's face before its eyes turned glassy as the spell tore a hole through its chest... not so much.
The goblin's behavior before its death also told Rei that while the Horn summoned the goblin, the basis of its loyalty to the summoner was vastly different than what a real summoning spell did.
Despite that, Rei didn't really feel much discomfort when he killed the goblin. There was no pity, no revulsion, no regret. Indifference was all he could feel as he looked at the humanoid corpse of the creature. This realization only hammered down the fact that his mentality was affected quite a bit and Rei decided he would have to be careful with how he thought about people. Deep down, he wasn't all that comfortable with the thought that he could now kill humans and not feel anything. As a former human, he decided to at least be logical about it and not go on any sudden killing spree.
Unknown to Rei, it was then that the butterfly effect started and Nazarick's actions would never be the same as in the canon.
...
The swearing of fealty and Sebas' report of the Nazarick's surroundings happened exactly as in the canon with a few notable exceptions.
Firstly, Rei was present and the guardians swore their fealty to him too.
Secondly, Solution was present and while she swore her fealty to Momonga too, her demeanor told her intentions clearly. She was first and foremost loyal to Rei.
This silent yet blatant declaration naturally didn't sit well with Albedo while the other guardians didn't seem to care. After all, Rei or Momonga, for them, both were Supreme Beings.
It took an intervention from both Momonga and Rei to stop Albedo and Solution from resolving their differences in an old-fashioned way. Both Momonga and Rei could only sigh in exasperation at the overzealous females before they decided they are too mentally tired to do more tests or even have a talk about their situation.
"Why do you find such a pleasure in antagonizing Albedo?" Rei who sat on the couch in his private quarters asked Solution who sat opposite him across the small coffee table between them. And damn if it didn't take Rei at least ten minutes to finally persuade the girl that yes, he would be more comfortable if she sat down rather than hovering around him all the time.
"I don't underst-" Solution started speaking in a startled tone but was quickly interrupted by Rei.
"Ah, ah, ah. You are indeed a good actress, Solution. Completely professional and outwardly indifferent to everybody. A perfect image of a maid. But it's your eyes that betray you." Rei mischievously smiled and leaned forward, " 'I am sorry, Albedo-sama, but serving Rei-sama is what HeroHero-sama created me for.' " Rei repeated Solution's words to Albedo that sparked their brief fight. "Despite your polite and calming words aimed at Albedo, your eyes betrayed your contempt and that's why she was so pissed." He informed Solution. "You can't hide these things from Succubus. She can smell it. You might have as well slapped her right there and then. Next time, try to lower your head and don't let her look at your face when you are lying to her."
Rei found this Solution Epsilon somewhat different from her canon counterpart. She was... confident. Not overbearingly so. No... she had this silent confidence around her that sadly caused some problems. This Solution had no problem with confronting Albedo because she knew she could take her on in a fight. She might not have look for confrontations with her supposed superior but she was definitely not afraid of them.
Solution thought of the advice she just received before smiling, "Thank you." She nodded in gratefulness. Solution had no idea that Succubi were so good at spotting lies. Bowing her head would also go well with her role as a maid so it won't be noticeable. "As expected of Rei-sama." She quietly whispered to herself.
Rei obviously heard her praise too and inwardly sighed. The second he saw how Albedo and Solution look at each other, he knew these two won't get along no matter what he tried. They could be polite and pretend everything was fine but that would not solve the problem in the long run. Instead, Rei decided to advise Solution on how to 'trick' Albedo's innate senses as it would at the very least reduce the number of confrontations between them since neither would have a reason to start one. He knew Solution would keep herself in line as was required of a maid. He just didn't believe Albedo would do that too since she had a higher position in Nazarick.
'Ah, well, once Solution's strength is revealed, many things would change. I thought the NPCs would be aware of each other's power but apparently, that's not true. Granted, I never revealed her exact strength even to Momonga so maybe that's the reason?' Rei mused.
"Well, I think it's a time for bath." Rei said to himself and stood up from the couch, heading towards the bathroom, leaving Solution to her own devices on the couch.
Inside the bathroom, Rei took off his gear and looked into the mirror. What greeted him was a quite handsome face with high aristocratic cheekbones... Rei simply couldn't help himself during the character creation... semi-long black hair, highlighting his pale complexion, and bright yellow eyes with slitted pupils. Unlike most Nazarick's guild members, Rei's character looked outwardly completely human except his eyes and it was also on purpose on Rei's part.
For a bit, Rei stared in satisfaction at his lean muscled upper body. 'To get a body like this without exercising... I really did pick the best world.' Rei proudly smirked.
He didn't make his character an epitome of beauty, however. Rei firmly believed that the most beautiful thing in a room should be a female and if it was not so, then something was extremely wrong. While handsome, his character was still in the realm of believability, good enough to fit in during parties of nobles but also capable of blending into the crowd.
It was then that the door to the bathroom opened, surprising Rei, and Solution calmly walked inside. Rei was about to freak out but she spoke first,
"Would you fancy a slime bath, Master?" Solution asked with a straight face as if she didn't just barge into the bathroom while knowing he was there.
Fortunately, Rei was used to the concept of a maid preparing a bath for her master. He was quite wealthy, after all. That said, he never really asked these things from his servants so having Solution doing this was still a new experience for him.
'Slime bath?' Rei tilted his head, still trying to calm his shocked heart, 'Isn't that the thing Nishikienrai invented for the guild? The same where he threw multiple level twenty acidic slimes into a tub and said it was a bath? The NPCs actually believe it is a true way to bathe?'
Somehow, Rei had a great urge to refuse the offer to be cleaned by an acidic monster but... he was curious. Too curious for his own good.
'Damn...' Inwardly cursing, Rei unsurely spoke, "I... I think I could try it once."
Solution's expression perked up, "Then, please remove your remaining clothes and sit in the tub."
"Er..." Rei was not really comfortable with removing his underwear while Solution was in the room but... he also had a feeling that no matter how he complained, it wouldn't matter. In the end, he decided to recognize this as his defeat and did as she asked, closing his eyes as he waited for the acidic slimes to be poured on him.
Logically speaking, Rei knew level twenty monsters won't do any damage to him and he indeed wanted to know how it would feel. So far, the differences between the game and reality were very pleasing so maybe this would be too?
Rei was pulled out of his reverie when he heard clothes impact the floor, causing him to open his eyes... his jaw almost fell to the ground.
"Wait! Why are you undressing?" Rei barely managed to not scream.
He didn't get an answer, however, as the curvaceous and very naked form of Solution enticingly walked closer to the bathtub, swaying her hips while her eyes were firmly locked on Rei's form, showing a measure of embarrassment deep in them. When she was near the tub, Solution's body suddenly rippled and transformed into a blue gooey substance, springing into the tub and completely engulfing Rei's entire body except for his head, making him instantly feel the heavenly comforting feeling as if he was being massaged all over his body. His muscles relaxed and enjoyed being gently kneaded. His nerves started tingling in comfort. His skin was carefully caressed...
Rei couldn't help but release a small moan as he closed his eyes from the sheer satisfaction and let his head rest on the edge of the tub, just enjoying Solution's ministrations. It was only then that Rei understood what Solution really meant when she offered him a slime bath. Alas, he felt far too relaxed to care.