Nzr150cc

After defeating the fallen god-king in divine war, Ziel Grisel (Ken Nijisaki) is cursed by his opponent and loses all his emotions. Ken feels the emptiness in his life and decides to create reincarnation magic by using his innate ability to dispel the curse.
Nine hundred years have passed, and Ken has been successfully reincarnated. Unfortunately, the curse cannot be removed, and Ken is forced to live in that era without his emotions. After learning that fact, Ken is determined to live a quiet and peaceful life as... a butler?

Invincible Colorless Butler

"Who are you!? How did you get into this room?" King Leonida became alert when he heard the voice and quickly drew his sword. He didn't notice Ziel's presence until the other party spoke. King Leonida thought that Ziel must have an artifact that could hide his presence, which was the most reasonable explanation for the current situation.

"You don't need to be so wary because I didn't come to hurt you. If I wanted to do that, shouldn't you already be a corpse in your seat?" Ziel responded calmly and ignored the sword pointed at him. He walked over to King Leonida and sat in the chair next to him.

King Leonida raised his eyebrows when he saw Ziel's face because he was no stranger to the boy.

Chapter 15