Hello, i did this mod, its not finished ( i don't know if will go further or atleast do everything)
here the song which changed
all the sont listen below activated once transformed

Ichigo shikai  = number one
Byakuya = reminescence
mayuri = invasion
yamamoto = Yamamoto Fight Theme (Gotei 13 Soundtrack)
ishida = quincy's craft (a remix a bit more "epic")
kenpachi = kenpachi bankai theme tywb
shinji  = the song he got while using his bankai in the ep 10 of tywb
sui-feng  = Sui-Feng vs BG9 Theme
aizen = treachery
Ulquiorra third transformation = ost B07a
gin = torn apart
rukia= never mean ton belong (an epic version not the version from tywb , who know if she come as dlc)

The menu got the OP 9 as music, Bonus have will of heart, story mod have OP 1 , menu for online and offline its the song Creeping Shadows, champ select is OP 2.
i changed the music from training map its battle igniton, the music (sorry i don't know the name in english) for the map in the human city i forgot the name sorry if some can help after listenning, the music for the map in the forest of soul society is BL_86.

Some loop are not very good i don't know why actually maybe i missed something (yamamoto, sui-feng and ishida if im not wrong)

more will be probably added later!

sorry for my bad english !