Chrysalis - Chapter 1472: New - Old Friends

Yeon-woo had a twin brother who disappeared five years ago. One day, a pocket watch left by his brother returned to his possession. Inside, he found a hidden diary in which was recorded “By the time you hear this, I guess I will be already dead….”

Obelisk, the Tower of the Sun God, a world where several universes and dimensions intersect. In this world, his brother had fallen victim to betrayal while climbing up the tower. After learning the truth, Yeon-woo decided to climb the tower along with his brother’s diary.

“From now on, I am Jeong-woo Cha.”

An innocent boy from Earth who was sheltered all his life finds himself reincarnated into a world full of magic, a world as beautiful as it is horrifying. Fate brings him together with his new loving mother and sister, and they face the trials together as a family. Follow their incredible story as they struggle to survive and create a better life for themselves.

Yo, Hi! I’m Frank, I made a deal with a demon to pay me some money for receiving a guest for a few days every week.
I had no idea about what I have done.
On May 1st, Conan ‘the God of Death’ came to my house. I was forced to let him in and we get involved in a criminal case.
On May 8th, Bruce Wayne ‘Batman’ came to me. I was forced to follow him to fight crime.
On May 16th, Hannibal Lecter, The Silence of the Lambs, came to my home. I can only say that I really can’t stand my guests.

- Description from Novelupdates

You take up a student career.

Student career upgrade to lv.7

Acquired skills: primary school knowledge, junior high school knowledge, high school knowledge.

You take the college entrance examination,

You got a perfect score.

Your basic occupation has been upgraded to lv.9, and the job transfer system has been activated.

You change jobs to become a scientist, you gain R&D skills

You use research and development skills to get space fortress construction technology

You use R&D skills to gain starship technology.

You are invincible.

- Description from novelbuddy