It wasn't just putting on a mask, it wasn't just taking another form.
It was becoming someone else entirely.
Every time he put on one of those cursed masks, the same three notes resounded through his mind, the three haunting notes that made up The Song of Healing. It was supposed to be a soothing melody, a healing melody, but it only reminded the hero of what had been lost.
He didn't just take the shape of a Deku, a Goron, a Zora. He became the Goron hero Darmani, he became the famed guitarist of The Indi-go's, Mikau. He was forced to live as they did; he was forced to live a lie.
He hated it, he hated lying to the people who knew the beings whose faces he wore as his own. They deserved to know what happened to them, to know the sad fate that befell them. He promises himself he will tell the sad tales next time he meets with the Gorons, or the Zoras, but every time, he can't.
How could one break Lulu's newly mended heart? She had just gotten her eggs back; she had just gotten her voice back. She looked at him with such thankfulness, such hope, and perhaps- dare he say it?- love. He couldn't do that to the beautiful Zora. She deserved to be happy.
How could he upset Goron Elder's son again? The child had just gotten his father back, and he looked upon Darmnai with such admiration, how could he ruin that? Did he have the right to take away a child's dreams?
No. After all the pain he had seen, hate, he would not crush a source of such goodness. He couldn't.
He was faced with a different struggle every time he became Deku Link. Every time he brought that mask up to his face, he was sent back to that cavern, where he had been forced into another form against his will, the Skull Kid's childish laughter echoing in his ears.
He remembered being so confused, stuck in a body that was not his own, a rude fairy his only companion. He had been scared. Ha, imagine that. The hero had been scared. He had wanted nothing more than to return to his body, yet he ended up finding another great adventure.
Perhaps one day, he would tell the truth and end the lies. Perhaps one day, he could lay the masks to rest and ease the burden upon his soul. But that day had yet to come, and for now, he would endure his suffering.
