Pre-Final Level Music Fade-Out

[TheYellowArchitect]

Music Fadeout happens at the end of each level, when dialogue starts.

For the level before the end duel, the music fadeout should happen when you enter the final corridor, and on the condition it has flipped.

I haven't done it because MusicSoundManager is absolute shit, untouched since 2018. Barely can be called a state machine, needs 2 new flags.

The greatest issue is not adding 2 new flags, but playtesting for an hour+ to ensure music didnt break (aka to ensure no regression bug)