Toradora! - Volume 10, Chapter 1

A teenager who obtained a life simulator, with the help of the life simulator, went from an inexperienced martial artist to the peak of cultivation, seeking immortals and chasing gods, paving the way for all living beings, and eventually becoming a generation of Taoist ancestors. [Avenue is fifty, Tianyan is forty-nine, escape to one of them! Therefore, everything in the world has a chance of life! ]

Sixteen years old: You broke through the ninth-rank martial artist, in order to deter all the enemies with ulterior motives.

Two hundred years old: You broke the bondage of heaven and earth, opened the body of the gods, and witnessed the way of immortals.

Three hundred years old: You realize the nature of heaven and earth, and prove the way of heaven and immortals.

Seven hundred and eighty-six years old: You have five proofs of the immortal way, one step to the sky, and the position of the monarch.

…

After countless simulations, [You have opened up an immortal path for all sentient beings and are respected as the Taoist ancestor. ]

- Description from novelbuddy

I just want to be different, no one can guess what I want to do, the more mysterious the more powerful.

- Description from novelbuddy

“Who are you lady?”

“How rude I am the goddess of reincarnation!”

A normal young man found himself surrounded by thousands of gods who were observing him silently.

“Shit... did I die?”

“yes... I know it must be hard-”

“LET'S GO GIVE ME MY HAREM AND OP ABILITIES LET ME EXPERIENCE COCKY EGOTISTICAL PEOPLE WHO WILL CALL ME TRASH NO MATTER HOW MUCH I PROVE I'M OVERPOWERED!!!”

Dead silence... Thousands of gods were left speechless.

“ok give me my system or infinite magic or unique bloodline or whatever”

Hearing what the young man said thousands of gods burst into laughter.

“I the God of strength will give you my system”

“I the God of life will give you my system”

“I the God of archery will give you my system”

Every single god gave the young man their system/power causing a unique system to be made just for him.

[Supreme System]

Another entry in what you can call the Proto Harem Series: the books written before the Harem Series that take place in the same world.

It’s about a swordswoman whose student is captured, so she goes to rescue her.