I think a good one for Sau would be 'Walk away from the Sun', but that's just me! cx It feels very inspiring for future plots for him, maybe when he gets older.
https://www.youtube.com/watch?v=PfJLFPBl_E0
For Clover and Sau, When the Day met the Night by Panic! At the Disco. *runs away*
One I think fits Clover perfectly is Girl in the Garden, and it fits how dreamy and story-obsessed she is.
https://www.youtube.com/watch?v=FNb0O8F6x38
I feel like No Consequences would be good for Fang, haha! How she just wants everything and doesn't care.
https://www.youtube.com/watch?v=Weq-zCfcfuo
For Basil....Grenade. Yep. ;3; He's an idiot.
https://www.youtube.com/watch?v=DNMWOFumnn8
For Tamelyn, definitely 22! Girly without meaning to be, adventurous, directionless and happy.
https://www.youtube.com/watch?v=urn9onLqMu0
For Vazi...For when he's innocent, Shh by Frou frou.
https://www.youtube.com/watch?v=5EIT_GqoyGE How he loves Wyn, but is still just a little bit irrationally paranoid. For the very very end, when he turns evil, maybe Sin with a Grin.
https://www.youtube.com/watch?v=PdKfpYEDvK4
Or maybe if that seems a little too violent and crazy (I don't know precisely
how crazy he'll become), maybe The Phoenix by Fall out Boy. Rather a call to war rather than murder murder murder.
https://www.youtube.com/watch?v=9kP0gO48HLY
Will add more here later! c: