I had a thought at that went like "What anime songs would work as the theme for every volume of this fanfic of mine future and present?" and so... I compiled a list of songs that I think would work. I don't own any of them and all credit goes to the owners of each of the songs. I just made this to set the mood of every volume.

Volume 1:
Op:

https://youtu.be/OXXtMO91Vh8

Ed: 

https://youtu.be/8KHGsjXXJlY

Volume 2:
Op: 

https://youtu.be/GC0cC8raAJI

Ed: 

https://youtu.be/CTW96mss_oo

Volume 3:
Op: 

https://youtu.be/HyKvcfeiF90

Ed: 

https://youtu.be/W2oBwgsAa4U

Volume 4: 
Op: 

https://youtu.be/tLy5FtLdZtI

Ed: 

https://youtu.be/Gz9cTIm6z4w

Volume 5:
Op:

https://youtu.be/rdCCebg8gtE

Ed: 

https://youtu.be/r1fA2dfN4-o

Volume 6:
Op:

https://youtu.be/v72zoaQVTg0

Ed: 

https://youtu.be/XVuydzqDAxU

Volume 7:
Op: 

https://youtu.be/HI2Wd0R4lqQ

Ed: 

https://youtu.be/QQj1YBlFQm0

Volume 8:
Op: TBA

Ed: TBA