You possess the ability to create, shape, control and douse flames at will. You are able to, with no effort, freely shape, control, and douse any kind of flames including supernatural expressions of it such as Amaterasu or Shiranui but are limited to simply creating normal flames with just this ability. You may create fire at any point you look at and if you possess any other ability to create any kind of fire, you can now generate a far greater amount of it.
Project V17/Powers/Shardless/Eternal Mangekyō Sharingan Abilities/Mangekyō: Kagutsuchi
From Worm CYOA Wiki
Kanayago
Your incredible control over flames has now been spread to all of your other abilities. You can perform things such as reshaping your Susanoo into a dragon, shaping and condensing it into a personal armor to amplify your personal defense or grant it extra arms and armaments. You also can give yourself voluntary invulnerability to any ability you posses, meaning you can make yourself invulnerable to the flames of Amaterasu, if you possess the ability, so you could do things such as coating your body with its flames to prevent anyone trying to touch you. You may remove and reapply this invulnerability at any time, in any form, individually to any ability you posses. You can also cast any ability you possess at any point within your eyesight.