What doujin novel? There were Dragon Ball, Grim Reaper, One Piece, Naruto, and the male lead had to be invincible.

I recommend " The Big Boss of the Saiyans ". The main character is Kallis, who has been reincarnated as a Saiyan. His combat power is only 1 point at the beginning, but he continues to evolve through the use of speed cards and other means, eventually becoming a powerful Saiyan boss. The novel was a comics genre, and the details inherited the Dragon Ball world view. There were many benefits, and he could use a full series of soul skills. He could even get Dragon Ball Super Saiyan fur. The book is over 1 million words long. Those who like power should not miss it. I hope you like my recommendation. Thank you.