Like a sudden change in mind?: That would never happen, Instead: MF: I LOVE YOU AYA!!! -sudden change of mind and kills Maria- MF: You were always my doll maria!
That's what we were getting to because if you search Tchaikovsky's Melody there are a few that appear, but it's not this song. It's more "happy" I suppose.
The game it refers at it like "tchaikovsky's melody by amacha music studio" and actually this a cut version, I found a extended one years ago exploring in Japanese free music directories, his tittle was in Japanese and just discovered that some of Mad Father's songs are actually cut and shorter versions of original ones, sadly I lost the songs and links because it was a long time ago but I'm sure if you start searching by songs details in game's gallery you will find them, if I remember the page was of a green color
They say it's called Tchaikovsky's Melody, but with that name I can't find the song on youtube, only when combined with Mad Father. But does anyone know the official name for the song?