The Undying Mecha Emperor - Chapter 267 Teacher

This story is centered around the man named Yi Ji-Hyuk, who has spent 1000 years in a Medieval Western fantasy-like world before returning back to the modern-day Earth. When he returns, he finds that his home is facing monster threats, and that humans with superpowers have appeared to protect the innocent people of Earth.

There was once an immortal cultivator fighting for the fate of human beings. Unfortunately, he failed that time; but fortunately got another chance as he was reborn once more as a human, on the earth of 5,000 years ago. With a second chance, he not only would embark on the road of saving all mankind, but also would retrieve his human nature on the new journey that would last for 5,000 years.

- Description from Novelupdates

“Stop following me!” Asher yelled, his patience running thin. He had let it slide for too long because she had done a lot for him. But now she was everywhere, suffocating him.“I’m only trying to protect you,” she responded.Asher sighed, running a hand through his hair. “I need some space, alright? I can take care of myself.”She didn’t budge, and just kept staring at him with that same obsessive look, like she had no intention of leaving.“Is it because you’re strong now? Are you going to leave me because I'm no use to you anymore?” Her voice had turned cold, sharp enough to cut through the silence.“Of course not, you know that’s not the reason…”“Then why do you want me to stop following you?”“I’m just going to the restroom, for God’s sake!” He massaged his temple, clearly at his wit’s end.“Oh, you should have said that earlier.” She giggled, the earlier tension melting away.“I did,” he sighed in defeat.