The World seems Realistic but Why do I have a Leveling System?

Inside the Trial Tower, on the First Floor.

Sheila pulled out the Taming skill book out of the inventory before putting her hands onto it which caused it to shattered like a glittering light in the night sky. And within her mind, a new set of memory has embedded itself deep into her brain. With this, now she could tame any sort of monster, so long as their strength is weaker than her, after all, the stronger they are, the more they can resist from being tame. But first, she needs to buy the items from the system's shop before she could actually use the skill to tame the monster. It required one special note that cost around 1k gold, since she had more than enough for that, Sheila bought a couple of them before taking out one for her experiment. 

"I have the note, now I need to inscribe the taming runes into this note using my own blood as the ink. After all, I'm the one going to tame the monster."

Once Sheila had given a small cut into her palm, she used the blood as the ink to inscribe the taming runes she had learned from the skill onto the small paper note she had bought from the shop. It didn't take that much time before she completed it, once that was done, Sheila brought the low-grade health potion out before drinking it to heal the small cut on her palm. Afterward, Sheila spread her awareness to the surroundings, searching for a single slime. When she found her target, Sheila immediately sprints towards it with the note in her hands. 

"Good evening, slimy friend. Ah, don't bother launching yourself at me, it won't even scratch a drop in my health point."

Though Sheila said that, the slime didn't seem to understand her word as it continues launching itself into her stomach with the intent to kill her but to no avail. It only makes it seemed much cuter in Sheila's perspective. Before the slime could launch itself again, Sheila had it bound on the spot before stamping the note onto the slime jelly-like body as the runes started to shine before enveloping the slime, though it tried to resist against the taming force, it was so weak that it feels like a drop within the ocean wave as eventually, it disappeared on the spot and the note flew into Sheila's hands. 

"Heh~ so that's how the taming process works, huh. And, hmm, within this paper note, there is a slime that has been tamed by me and if I wish to summon it, all I need is to throw this with the intent to summon it in reality. As to bring it back into the note, it was much easy as with one simply intent from me, it would return, huh."

With that said, Sheila immediately throws the note in front of her as she watches the scene in front of her with intrigues as, within the blink of an eye, the note was replaced with a single slime as it flopped onto the grassy ground. When it was freed from the note, it immediately took notice of her presence before jumping 'happily' towards Sheila. 

『 Unnamed Slime LV.1 』

『 HP: 20/20 MP: 0/0

Skills:

Absorb Lv.1

Self-Regeneration Lv.1 』

"Hmm? Isn't it much weaker than before being tamed? And it has two skills, must be from its race as a slime. Even so, unnamed, huh? I guess I need to give it a name."

Perhaps, it understood her words as the slime happily jumping around her which put a smile on her face. But a name, huh? I'm not that good with naming, I might ask for another opinion before naming it. For now, let's level it up first. 

"Do you understand my word? That's good, then shall we level you up first?"

With that said, Sheila walks forward with the slime following right behind her, thanks to the skill, though the slime didn't understand her word, it still understood her intention, same goes to Sheila. While Sheila was using her skill to bound the other slimes on the spot as the tamed slime attack them, she was pondering over the reward she had acquired from completing the previous quest.

『 Savior (Title) 』

『 

Increased all attributes by 5+

All attributes will be increased by 30% when saving/protecting someone. 』

"Heh, that's a pretty nice title. But the more important thing is..."

Sheila moved her gaze into the inventory as she looked toward a certain plate formation and thought, I was going to buy this in the shop but somehow I received it from the reward of completing the previous quest. The system must have known that I needed it, hmm, maybe there's a way for me to acquire something as a reward instead of buying it from the system's shop. But I don't know how the system works. But now that I have this with me, I need to buy the items required for the formation which is quite pricy but I had enough gold for that. 

After buying the required items from the shop as the gold diminished to as low as in the hundreds, Sheila heaved a relieved sigh. She didn't care about how the gold she had saved up so far had been used up, since this was one of her goals, after all. Suddenly, Sheila could feel something sticky around her legs and when she looked down, she saw the tamed slime rubbing itself on her feet which put a smile on her face while having the thought of how cute the slime is. 

『 Unnamed Slime LV.3 』

『 HP: 60/60 MP: 0/0

Skills:

Absorb Lv.2

Self-Regeneration Lv.1 』

Sheila nodded her head when looking at the slime's current stats. As to why the other skill didn't level up, it was due to the fact that slime never received any attacks from the other slimes as Sheila had bound them in places as it went over and easily absorb them into itself. The slime at level 1 was around the size of a volleyball and now that it has reached level 3, it has increased to that of an to that of bowling but much smaller than a football. Even its core has grown bigger but it couldn't be compared to the core of a Slime King which is around the size of a baseball. Sheila was happy at the growth of the slime, she even hopes that one day it would grow to as big and powerful as the Slime King, if it could go beyond that point, that's even better. 

With one simple intent from her, the slime suddenly shines before it 'transformed' into the runes note as it flew into her hand. 

"That's useful."

Leaving such words behind as she put the note into her inventory, her figure suddenly vanished from the Trial Tower before reappearing back in the room before flopping herself onto the bed.