Oh boy, here we go!
-The Scientist (Coldplay): A song that seems like a mixture of sad and loving as the singer seems to reflect on things of the past. Yup, that's Shabeke's theme.
-Zinnia's theme (from Pokemon!): I thought this could work as a battle theme for Shane, especially for when Abeke duels with him. It's some cool fighting music, but if you focus on the violin... it could carry a sad or regretful tone, like Shane doesn't want to fight Abeke.
-Remember You (from Adventure Time): A sad song that with some parody lyrics, could better fit Aidana singing to Rollan as she leaves him behind - both the first time when she struggled with her bonding sickness, and the second time when Gerathon possesses her.
-Thunder (Imagine Dragons): Someone else had the idea that this could be Rollan's theme, and now I agree.
-Ignite (from RWBY): This song plays as Meilin is fighting. Point of the song? Don't mess with Meilin.