Okay so just to clear some things up about the ending of this fanfic, I'll tell you what sort of happened.
Cupid pretty much sent everyone asleep and in this dream he created a scenario of something that could be if this, this, and this happened. Through out the fic Bianca is haunting Nico, Bianca technically being a part of his imagination that he created that knows that none of this is real. It's kind of weird and confusing but it was built up for the plot twist and I didn't have room to shove this sort of information in with a nice little bow.
Another thing! When Nico dropped his sketch book and things after Jason bumped him they were drawings of Percy and honestly I can't decided between letting you know if he was drawing hardcore stuff or just cute pictures of him at different angles and hero stuff.
Also, what happened in Nico's past for him and Bianca to have been traveling like that was left blank. This is an alternate reality (the dream) and everything is not always filled in, especially with the past, unless it suits with the scenario.
So yeah! I tried to cover all of your questions but if you have anymore I'll be more than happy to answer them!
Thank you all for reading! It is possible that in the future I will write more Pernico stuff but right now I'm working on a Chrisse fic c;