There is little Known about Narvi (old Norse spelling the e is long)/Narfi and Nari as they are only in one story in which they are killed, and their intestines are used to bind Loki, but I do think we can make some inferences based on the etymology of their names. Nari is fairly simple it means groin in old Norse, and I believe that may mean he had something to with fertility. In the prose edda Loki and Sigyn’s sons are said to Vali and Narvi but in the poetic edda its Nari and Narvi. It is generally believed vali being called Loki’s son is a transcription error because Vali is usually called a son of Odin. Though there is also a dwarf named Vali meaning it is possible they all share the same name, I prefer to use Nari to avoid confusion. As for Narvi, in old Norse the word Nar means corpse and ve refers to a shrine or sanctuary. This means his name could be translated as corpse shrine or corpse sanctuary which I interpret as meaning grave. This next part is purely my interpretation. Most death gods have at a psychopomp, Odin and Freya have the Valkyries, Ran and Aegir’s daughters are the waves and the wave are what take you off your ship into the realm and into the realm of Ran and Aegir so the waves can be interpreted as psychopomps, in Greco-Roman religion hades and Persephone have Hermes and Thanatos. This leads me to believe that Hel may have one as well. The underworld is generally seen as being underground hence the name and burying someone in a grave could be interpreted as bringing that person to the underworld, because of this I believe that Narvi may possibly be a god of burial and a psychopomp similar to Anubis in Kemetic religion. Furthermore, this would mean that Narfi and Nari fall into the Indo-European trope of twin gods who represent opposite concepts; Narfi being death and Nari being fertility and life.