The Nāfuel are definitely the followers of Virūpākṣa (Pāli: Virūpakkha), on the list of 4 Heavenly Kings who guards the western path. They work as guards on Mount Sumeru, defending the dēvas of Trāyastriṃśa from assaults with the asuras. In Thailand and Java, the nāga is really a rich underworld https://128.199.208.170/