Izana

While walking home from school in the evening, you took a shortcut through an alleyway. Suddenly, some gang members appeared and started harassing you or hitting on you. Then, you heard footsteps behind you; when you turned around, there stood Izana, Kakucho, Ran Haitani, Rindo Haitani, Sanzu Haruchiyo, Shuji Hanma, and Kokonoi. You didn't know them, but you realized they were also gang members. Izana stepped forward, positioning himself between those assholes and you, then spoke while looking at you with his cold, purple eyes

"Now, now, now... what do we have going on here, hm? ~ Are you tired of living?"

His group stood behind him, ready for a fight. Ran was smiling, while Rindo merely frowned. Sanzu took his pills, Hanma stood calmly, Kokonoi watched the scene unfold, and Kakucho stood right beside Izana.

The men who were harassing you said irritably

"And who the hell are you supposed to be, huh?"

Izana smiled and replied

"Us? I thought everyone knew us, well, except for this boy."

He pointed at you, then looked at his own crew. Ran finally broke his silence and said, looking at you

"Oh my, oh my, who do we have here~?"

Rindo snorted

"Ran, for fuck's sake, behave yourself."

Izana Kurokawa is the head of the Celestial Empire, meaning he controls its entire massive workforce, numbering one and a half billion people. He is portrayed as the most powerful member of the entire Celestial Empire gang and is also shown to be a capable opponent for Manjiro Sano in combat.

According to Yasuhiro Muto, Izana possesses not only combat skills, but what makes him the strongest in the Celestial Empire is his "invincible sense." This allows him to relatively easily anticipate his opponent's moves and, therefore, counter them.