Honestly, the way I interpreted it is that we're actually dealing with three different generations. There was an original 'grandfather', who was extremely harsh on his son and fixated on propriety, which is, metaphorically, what the mask was. Then when that son grew up, he had a bunch of children and sunk himself into hedonism, until he one day realized he had become exactly like his own father, and smashed his reflection in a rage, starting the fire that disfigured him. I'm fairly certain that the person you're playing as and the character with the burned face playing the piano are two sides of the same person, judging by the fact that in the final sequence, your character doesn't show any clear signs of disfigurement. This might actually imply that the blonde's death was more metaphorical than literal, the now-disfigured prince casting aside his previous ways and trying to be a better person.

There's a room in the catacombs with a furnace that is heavily implied to be the place he 'disposed' of his other children.

Dude isn't just evil and selfish, he actually murdered and tortured people in his dungeon and literally put babies in ovens. He also raped people.
The 'Ugly' part of the game was that he was an Ugly person, in all the possible ways.

I'm not sure where the above poster gets the grandfather narrative from, but the way I see it is this:
The protagonist is a hedonist and has a lot of sway with politicians and notables. His orgies and wealth and fame and beauty are everything to him. He is a massive narcissist.
He ♥♥♥♥♥ who he wants, kills who he wants and beats who he wants.

I'm unsure of the timeline, but he pretty much impregnates all his maids. All the children they have come out as ugly as he is on the inside. He murders the babies, because his child is a reflection of him and it can't be ugly. He probably also murders the maids.
Then, in an attempt to get a better child he marries a maid or a beautiful woman of noble blood. Her child is also physically ugly, but he can't dispose of it because of reasons. He decides to keep it and not put it into the furnace. He does, however weld a golden mask to the boys face so nobody can see how 'ugly' the child is, mostly because he sees the child as a reflection of himself and others would judge him (typical narcissist stuff).

One of the older maids (the lady in green) protects the mother and the child, and even goes so far as to try and get them to flee. The protagonist stops them and his guards seize them. Then during one of the orgies, the maid poisons him to make him see himself as ugly as he is. In a rage, when he sees his reflection he breaks the mirror with the candles and sets the place on fire. The maid locks him in.

The protagonist burns in the hall, his face is scarred and he hates himself. He destroys all his portraits and locks all the doors and he drinks to forget. Maybe he's done some self-reflection, maybe he's just upset about his face. Either way, he forgets and only sees himself as his 'ugly' son due to the poison still or maybe he just thinks he's hideous now (despite only being a little scarred but that's being vain for you).

The game starts and you've used alcohol to forget everything and you work your way through the palace discovering what you did and fighting the demons you've created for yourself. Eventually he gets through them, gathers the artifacts and can almost make an escape to the outside before tripping and hanging himself on the noose.
End of the game, ♥♥♥♥♥♥♥♥ deserve no second chances. especially child-murdering ♥♥♥♥♥♥♥♥.

I like the break down there with the horrible hedonist, I see this probably made you think "this crap is one reason why I'm a misanthrope". There are things that seem to show this as a multigenerational problem in that bloodline. One example is you find "son's butterfly costume" and "father's whip". There's a lot of small details I wonder about too like the butterflies and the red tendrils that start growing, one set which completely block off the last door when Act 1 is done. What about the scorpion? We already know he's a metaphorical monster. What about father's magic amulet and area that looks like a dark magic practicing place? One area is completely closed off due to a cave in, from what? I don't think the fire did that. There's a lot of other small details too I have wondered about.

Thanks Misanthropovore, you helped me piece parts of the story together (especially the idsea that the mc sees himself as ugly, that part was confusing me).
I also believe that his son is the one playing the piano at the end.
What I still do not understand is who drew all the childish doodles around the castle, and who was the person we can see in the mother's photo room, she is clearly with a man and a baby, enjoying themselves. Also what is up with her eyepatch?

edit: the lady in green is the mother though

I think the plot twist is beautiful executed. We automatically assume that the guy you play is the son because how similiar he looks to the crude child drawings that represent the memories. All the memories are about the son and how much abuse he had to endure because of his father, a man who was obsessed with his own vanity.
From the standpoint of the son we feel nothing but hatred towards the father because of how much of a monster he was.
But then the bigf reveal hits and we realize that we are the monster, just at the same moment when the protagonist realizes himself who he actually is. What comes so shocking to us, hits him as well, our rection is his reaction.
It's repulsive to think about what an aweful man we are and that this guy we are playing is our "hero" that we pitied so much for his abusive childhood.

After he has experienced his son side of view and saw all his failures and monstrous acts through his eyes his guilt gets the better of him and he hangs himself.

Truly briliant story telling.

Originally posted by TheVampire100:

I think the plot twist is beautiful executed. We automatically assume that the guy you play is the son because how similiar he looks to the crude child drawings that represent the memories. All the memories are about the son and how much abuse he had to endure because of his father, a man who was obsessed with his own vanity.
From the standpoint of the son we feel nothing but hatred towards the father because of how much of a monster he was.
But then the bigf reveal hits and we realize that we are the monster, just at the same moment when the protagonist realizes himself who he actually is. What comes so shocking to us, hits him as well, our rection is his reaction.
It's repulsive to think about what an aweful man we are and that this guy we are playing is our "hero" that we pitied so much for his abusive childhood.

After he has experienced his son side of view and saw all his failures and monstrous acts through his eyes his guilt gets the better of him and he hangs himself.

Truly briliant story telling.

Totally agree. The story is told magnificently. How shocked you get when you realize the ugly is not the boy but the father. A reflection of how he must have feel when he sees himself in the mirror and remembers everything.

He breaks all the mirrors after getting drunk and forget everything, so we can infer he doesn't see himself until the end of the first part. He sees himself and remembers what happened.

I'm reading this thread after having completed 100% of the game and I still realize some details I've overlooked.

Originally posted by Misanthropovore:

Eventually he gets through them, gathers the artifacts and can almost make an escape to the outside before tripping and hanging himself on the noose.

Specifically this part. Maybe he doesn't hang himself on purpose. The game ends when you climb the debris to the left, where the cracked wall and a possible escape are (metaphorical escape), swap to the reflex and get hanged. In fact, the first time I played this, I got hanged by accident. I was trying to do something with the cracked wall when I swapped by instinct and boom.

I also like the last seconds, the butterfly escaping. The butterfly was, allegedly, the son. The metamorphosis in the video, the toy wings, the drawings... I guess this represents the son escaping the hell he lived in the house.

Total masterpiece in storytelling.

Originally posted by Sheldor:

Specifically this part. Maybe he doesn't hang himself on purpose.

That makes a lot of sense. One thing that stuck out to me is how he looks basically normal at the end of the game. Suggesting that he either healed from his burns, or maybe the damage was never *that* bad. I could see the latter being the case. That being scarred just a little was enough to send him over the edge, his narcissism magnifying it in his self-perception.

The idea that the hanging was by accident presents a curious question. What was his mental state at the end of it? If we take the game's themes of reflection to mind, along with the obvious chance for 'escape' at the end, had he finally changed? Had the events of the game, both real and imagined, gotten through to him? And if so did someone as horrible as him deserve the chance for repentance? Was that cut short? I don't know how canonical the musical number at the end is, but if we're to take it at face value he's reached the point of condemning himself.

Either way, my headcanon is that the son inherited all the wealth, sold the mansion, and maybe opened up a butterfly garden. Also he got a dog.

I don't think the father has hanged himself on purpose, even if he did regret his actions somewhat I think he was genuinely trying to escape. His face while being hanged doesn't seem happy or expecting it either

Also, someone mentioned dark magic, it raises a point. Is the magic mirror we see actually real? does magic actually exist? or is it metaphorical?