Not Rinnegan but Masashi Kishimoto's glossing of a broken kekkei-genkai in his series Naruto left a chain of unanswered ...

Each character possesses unique talents and abilities, often linked to their bloodline or Kekkei Genkai. Hard work and dedication, along with innate talent, contributed to their growth as powerful ...

Naruto starts fairly tame in terms of power, with most ninja having access to only a handful of elemental-based jutsu unless they were also gifted with a kekkei genkai or other special technique.