I actually have a very specific headcanon for how Will Solace ended up at CHB that I don’t really talk about much in-depth (besides some little inklings of it on Deadangelos here and there) because of how he’s only introduced in TLO, so I figured i’d get into it.

Because we know Will isn’t a camper in BoTL but is in TLO (and was made counselor because he literally only had two siblings left), I headcanon that he joined camp in the off-season the winter after BoTL.

Basically, I figure Will got into a fight with some bullies at school, not necessarily because they were bullying him (because people tend to just kind of generally like him) but because he’s the kind of person who calls people out on their BS, and he got so mad that he accidentally caused some kind of minor plague. Either a plague of rats or locusts or just plain old weird case of like The Black Death. Whatever happened, obviously nobody assumed it was him because that seems physically impossible, but his school ends up closed down for a bit so Will has to find a new school. And cause he’s twelve and his powers are starting to ramp up more and he has to find a new school anyways (and maybe Naomi is about to go on tour and isn’t able to help Will find a new school at that moment) they decide it’s time for him to go to CHB and that he’ll be a year-round camper unless he gets sick of it and really wants to come home in the off-season. So Will goes to CHB in the middle of winter and immediately it sucks. It’s that kind of sleet weather where all the snow is grey and wet and keeps freezing and unfreezing. It’s annoyingly cold but not really cold enough for a heavy jacket and it’s cloudy and dark and the sun sets by like 4. And Will’s from Texas and an Apollo kid (never seen snow before and solar-powered) so he’s immediately miserable and Argus has to basically drag him from the airport to camp.

And then when he actually gets to camp it turns out he’s the only Apollo kid there. Because year-round Apollo kids are basically unheard of (given their powers are generally mellow enough that they’re fine going home for the off-season and Apollo kids are notorious snowbirds anyways) (and canonically there were no year-round Apollo kids pre-TLO). And it’s the dead of winter between BoTL and TLO so camp is particularly empty with like probably a dozen or so campers total. So Will is stuck in an empty cabin feeling miserable and there’s barely any other campers to make friends with (and even fewer his own age, since he’s at that point one of if not the youngest kid in camp). He tries to make friends regardless and Drew immediately adopts him as her best friend (and he doesn’t really get a choice in the matter) and Chiron ends up taking Will under his wing as a medic apprentice, which Will enjoys and it helps brighten his spirits a bit, which makes everyone else in camp feel a little bit better in turn because seeing a little happy sunny twelve year old Apollo kid running around healing people really helps takes their minds off their impending doom, especially while camp is the most barren it’s been in decades.

Then the other Apollo kids start trickling back when the weather turns and it’s a little awkward because Will has to get used to having siblings and not being in an empty cabin and the other Apollo kids have to get used to having a new sibling right after they all just lost Lee Fletcher (which Will is very mortified to learn about). And it’s even more awkward because they’re not used to siblings arriving to CHB while nobody’s there, so Will’s already used to camp and knows everybody except the summer-only kids so they don’t have to show him the ropes or anything, but also Will’s been doing everything by himself so it’s odd for him to adjust to having to listen to his older siblings. Weird feelings all around. (And extra bonus points if we’re also going with the headcanon that plague children of Apollo are considered bad luck, so Will feels extra bad about showing up right after the old cabin counselor died and right before the major battle of the war, and so refuses to tell anyone about his plague powers.)

It gets better for a bit when Kayla and Austin join camp a little before the Battle For Manhattan, cause Will isn’t the youngest in the cabin anymore and they’re both also year-rounders, but then it immediately turns sour when after the war suddenly those three are the only ones in the cabin. So now Will is traumatized and has to be in charge of his also traumatized barely-younger-than-him siblings, and he’s in an (almost) empty cabin again, and he’s only been at camp for less than a year and is still one of the youngest kids at camp. And he still doesn’t like winters in New York and he misses his mom.

Things turn up for him a bit after the war when there's the sudden huge influx of new campers, so he’s not the youngest anymore and he has something to busy himself with and camp is bustling even in the off-season. But for that first year Will just has an absolutely cruddy time, because man it must have sucked to be a campers joining in the middle of the Titan War.