Korekiyo is an aloof and somewhat creepy person, but he is also very cool-headed and intelligent. He can keep himself composed even under the confinement circumstances and believes in facing things with calm and rational approach rather than an emotional one. He has a vast knowledge of different cultures and ponders different subjects in deep and complex manner, with him occasionally starting lengthy anthropology speeches even though nobody asked. However, he does believe in ghosts and souls, and has a strong interest in communication with the dead and death in general.

Here are some voice examples: https://youtu.be/JgoVBUnR0UQ