Will rarely ever cried. It was hard, since so many kids have died in his care, one boy not even 11 years old yet.
Maybe that's why he couldn't let Nico do that to himself.
He still saw the 8 year old kid he once knew gabbering on about mythomagic somewhere inside of him.
That must be why he didn't flinch when he saw the boy with a black ukulele.
He didn't think twice when the boy in an all black shirt sprouting upbeat tunes.
One day when Chiron decided to have campers from all cabins do a talent show, Nico was dared into it by a certain kelp for brains with an obsession of blue food.
So even though he didn't think twice about it when Nico showed up with a ukulele, the others did.
He played softly for a few seconds before the song got louder with these lyrics;
"When the leader of the bad guys sang
Something soft and soaked in pain
I heard the echo from his secret hide-away."
(I'm too lazy to type out the rest so here )

After the song, Nico decided to explain some things.
"To all of you, this song is probably stupid. It has a good beat, I'll admit. But you see, children, the judge is yourself. You have to set yourself free. Free from your self doubt. Free from your imperfections. Free from your demons. You've got to set yourself free from yourself."
Will cried that day.