Tried finding this by searching for "Ryujin song" but it didn't work lol... had to listen to the first few seconds of most songs from the OST. Anyway, this is my favorite song in the game. Whenever it comes on I just find a spot to chill and let it play, while soaking up the sights of Neon City.
Should be a real voice as a basis and modified here and there a bit to shape it to the sound you hear. Would guess it because its hard to change between "a" and "e" vocal sound (not to be confused with the notes) with a synth in such a dynamic manner. But there might be some synth i dont know...
Starfield towns can feel a bit artificial with how small they actually are compared to their concept art but Bethesda are really good at evoking a certain 'vibe'. I remember this song playing while walking outside on the outskirts of Ebbside in the early morning after a long night of mind-melting, overstimulating light and audio in the core of the city. Watching Volii Alpha's unending downpour and grey clouds alongside the junkies coming off their high, it felt like a genuine place. For a town of vice that doesn't actually have a single casino or piece of skin on offer, that's quite a feat.