Based on a Tumblr thing I found cute.
Apollo kids can't be dealing with the lack of sunshine that winter entails, so Nico aids in keeping Will all toasty and warm.
Set about two and a half years after Blood of Olympus.
Nico aged around 17/18
Will aged around 18
Most characters features are not my own and are the invention and property of Rick Riordan.
Story concept is by thesquirrelisonfire on tumblr:
"It's winter in CHB and Will is wearing a really oversized sweater because Apollo kids are sensitive to lack of sun and then Percy or Jason come around and ask if him if he's seen Nico and suddenly his sweater starts wiggling and Nico's head pops from the collar and he's like sup"
Also, there's mentions to Nico having a 'thing' for blood in Chapter Six, I just kind of imagine Nico to be a haematophiliac.
I'm not implying tht Nico is going to go around killing folk and feasting on their blood to gain some kind of sexual pleasure- he's spent enough time around death without becoming a serial killer.
I get if people don't agree with this idea, but it's the first thing that popped into my head that the other characters could tease him a bit about.
I wrote that chapter at some ungodly hour, I was exhausted and my brain was fuzzed and I don't know why but I just don't want to change it.
Additionally, I just kind of figured that Nico would have sensitive eyes; because of all of his time in the underworld and whatnot.