Whether Ryūzetsu's eyes are related to her Kekkei Genkai or not is unknown, as she is the only person seen with this ability
This unnamed kekkei genkai apparently allows the user to perform Reincarnation Ninjutsu as it allowed Ryūzetsu to perform the Dragon Life Reincarnation technique. It was seen only in Naruto the Movie: Blood Prison and Ryūzetsu was the only known user. Other details, such as whether it was common or rare and whether any other technique could be performed using it, are unknown.
And while Ryūzetsu's eyes look very similar to the Rinnegan
Ryūzetsu had fair skin, waist-length white hair that is covered by a green bandana that has a long curved white stripe which had belonged to Muku and grey eyes with multiple circular patterns much like Pain's Rinnegan.
they are not the same. We know the ways to obtain the Rinnegan are
- The Rinnegan can typically be awakened by gaining Hagoromo's chakra either by reproducing it from combining the chakra of Hagoromo's sons, Indra and Asura, or by directly receiving chakra from Hagoromo himself
- As with any dōjutsu, the Rinnegan can be transplanted into others
Additional, those with the Rinnigan can master any jutsu and all 5 chakra natures
One who possesses the Rinnegan can easily master any jutsu as well as all five nature transformations
However Ryūzetsu is only shown using Fire Style.