Yes, there is a Ninja Kamui manga. It has gained popularity for its action-packed scenes and interesting character developments. Many fans enjoy collecting and reading it.
I recommend the book "Possibly a Fake Silver Soul". It tells the story of Jiang Cheng, a transmigrator, who met the owner of Xinghai District and his girlfriend, Jiang Hua, who were traveling in the universe in the dragon vein of a certain planet. Later, he came to Earth and met his teacher, Yoshida Shoyo, who had influenced his life. He also met a group of friends. This included the transmigrator Okita Soki. This is a Silver Soul Doujinshi novel, don't miss it. I hope you like this fairy's recommendation. Muah ~😗
Naruto using Kamui could change the power dynamics in the Naruto universe in the fanfiction. His battles would become more unpredictable. For instance, against strong opponents like Madara or Kaguya, Kamui could be used in creative ways. He could use it to send parts of their attacks to another dimension, or quickly dodge attacks and counter - attack from unexpected angles. It also might make his allies view him differently, as this new power is something very different from his normal ninjutsu.
Gintama is purely fictional. It's filled with imaginative characters and scenarios that are not rooted in real-life events. The creators crafted a unique and entertaining fictional world for the audience.