@demigod_of_the_sun okay, so if you want some ideas I have some!
1. Will takes Ghost King in and fixes his wounds and asks what happened and Nico tells him half truths and when Ghost King is all better, he leaves and Will has a bunch of question and decides to become friends with him or smth
2. Ghost King faints and Will takes him inside to fix him up and while he's unconscious, the mask falls off or Will takes it off and sees Nico. From there you can either have Will tell Nico he knows or pretend he doesn't.
3. Ghost King tells Will he needs help and Will takes him inside and fixes him up and Nico decides that Will should know who he is and they have a really cute moment with Will maybe scolding him for being so reckless and Nico still almost bleeding out and woozy and it could be some kind of tense fluff lol.
4. You skip over Will healing him and him and Ghost King are sitting in his living room and Will demands that he stay with him for 3 days (a little universe cross over) and then the next chapters are when Nico finally admits who he is and/or they kiss, etc.
These are just ones I thought of the top of my head so you can mix and match them if you want or pick one. If you want you can totally delete this chain if you want the chapter to be a secret and stuff. I'm also open to making a google doc where I could help you actually write it, I just want to help anyway I can <3