Through the power of the Eternal Mangekyō Sharingan you gain the ability to summon cold foxfire, which absorbs the heat of whatever it burns. This heat is stored within your other eye, and can be unleashed as a lance of flame. While the fire can be blocked, this lance of flame is able to penetrate most barriers once enough heat is stored within
Project V17/Powers/Shardless/Eternal Mangekyō Sharingan Abilities/Mangekyō: Kuraokami
From Worm CYOA Wiki
Takamimusubi
Your consumption of the sacred treasure of the Ōtsutsuki gives you insight into your Kurokami ability. It seems that this ability spawned from a strange mixture of Fire and Ice, a dichotomy not normally found outside of those with incredibly rare Kekkei Genkai, and a distinction that has now been spread to all other natures. You are free to mix whatever chakra natures you can learn, in whatever form you desire. Mix Fire and Water for acidic mist or steam, Wind and Water for ice. You can form multiple results from a single mixture such as Fire and Earth for Lave, Rubber, or Acidic Fluid. You may even mix natures against itself such as Wind and Wind for a more powerful variant such as Typhoon, or mix advanced natures with itself for more combinations.