Saturn has the Team Galactic battle theme and his possession Azelf has the Lake Trio's theme music which also comes with a very cool remix for PLA and I just wanted to link them all ok. Unisonya can probably hear a mix of all of these in Saturn because of how he's tied together with Azelf here.

I'm fine with her hearing anything! Azelf is an ancient Psychic-type Legendary Pokemon/god of willpower and Saturn is just a 22 year old normal human dude it's riding with lmao. Also in terms of Natures in the LITERAL POKEMON SENSE Azelf's Nature is Sassy and Saturn is a human so he doesn't have one but just for fun, if he did, I would say it's Lonely lol.