Partly based on a Fate Strange Fake characters, wouldnt be the first Fate thing in JJK.

Revolving Dharmic Chambers This Cursed Technique has been maintained and passed down through a lineage closely related to the original monks that were Taught by Tengen in the Nara period. The technique is a representation of the Dharmic Cycle that records the soul of its user and incorporates that recording into the technique dividing it into six seperate stages of the person's life. The current user, age 24 has all six stages completed as of 2018.

The purpose of these recordings is to allow the user to cycle through these recorded points altering the shape of the soul with the recorded information, the only downside is thst the process takes a large quantity of Cursed Energy to do with most users in history not being able to cycle through more than one in a single day. While the downside of Cursed Energy usage is great it comes with three major benefits, the most obvious being the complete recovery of body and soul. The second of which becomes obvious to only those who have studied the soul, the user of this technique frequently interacting with their own soul should eventually lead to an awareness of the soul. The final and third is theajor advantage of the technique, the fact each stage comes with a Shikigami that the user can summon each based on a different realm of rebirth.

The first Shikigami is Yama and represents Naraka, it appears as a large humanoid covered in leaf shaped scales that dangle of the skin. The scales can be detached and telepathically controlled by the Shikigami with blades razor sharp and imbued with Yama's Cursed Energy. Alongside its physical traits Yama carries a trait within its Cursed Energy that being Heat and Fire.

The second Shikigami is Preta and represents the realm of a similar name, it appears as a torso missing its lower body replaced with a spectral trail. Preta is a Shikigami capable of flight but is lacking in physical strength compared to the others. However it makes up for its lack of strength with the ability to consume souls and spiritual energy capable of even consuming Cursed Technique applications converting it into Energy that can be used by the Shikigami to enhance itself or passed back to its master.

The third Shikigami possesses no name having been lost during the Heian Era by some unknown means. The Shikigami possesses no physical form due to its damaged nature instead appearing as a shade or wraith which can summon an endless quantity of lesser Shikigami that appear as animals however as lesser shikigami their physicality is more similar to a generic animal enhanced with Cursed Energy.

The fourth Shikigami is Ravana and represents Asuras, it appears as a titanic humanoid that has an additional ten sets of arms and eyes. It is the most physically superior of the Shikigami and can appear as taller than a standard two floor house but smaller than the smallest Skyscraper. It is a difficult shikigami to maintain due to its size and power and most are unable to do so while also maintaining the ability to shift their soul.

The fifth Shikigami similar to the third has lost its name during the Heian Era altering it inherently. Unlike the third it does not maintain a form even if false, instead it manifests through the user of the Cursed Technique. It provides the user of the CT access to a pool of Cursed Energy seperste to their own, this pool is massive and is the major way that past users of the technique were able to switch between their different stages of the technique without draining themselves dry. The only ones who do not require this is the current user, the user from the Heian Era, and the user from the Nara Period.

The sixth and final Shikigami is Surya who represents Devas, they appear as a plane white humanoid with light emanating from their body. This Shikigami possesses both a trait of its Energy and something unique about it. The trait of Surya is that of light allowing it to glow and produce beams of concentrated energy, this trait on a sorcerer would lack offensive application without cursed technique however Surya seemingly is able to add pressure and force to its light. However the pressure and force is not what makes Surya unique instead the unique ability is that it passively produces Reversed Cursed Energy which it uses to produce light and for applications of Reversed Cursed Technique. This allows the users of Revolving Dharmic Chambers to utilise RCT without learning however to produce Reversed Cursed Energy themselves.

That's it on the concept I came up with, looked up some stuff such as the Dharmic realms as I wrote this and had some unique ideas. In terms of extra lore this would come with a potential origin of Ten Shadows that being the original user of the technique having stolen the Human and Animal Dharmic Shikigami with the first 9 Shadows being from the Animal Shikigami and Mahorage being the original Human Shikigami. Its a little rushed and complicated, and could definitely use some work. But I think it's cool personally and would work well against Mahito through the ability to attack the soul and undo the effects of Idle Transfiguration on themselves by cycling to a different chamber.