Before I go into the theories that have been bouncing around in my head I must say hats of to the team behind this magnificent story just (Chefs kiss).
1. Oscar/Storm is or at lest is a piece of Asterion's divinity that the god's took from him and was born when one the god's ( I'm thinking Hermes) got Oscar's/Storm's mother pregnant in order to Give Asterion his divinity back ( I'm only guessing about the why this seems the most logical). I am making this guess mainly on what the narrator said in Ch. 18 when Oscar/Storm and Asterion meet in front of the hotel "From the slit in the star-spangled horizon, he comes. The drop of blood" this i felt was a way to signal us as the reader that they are more closely related than it would seem a first glance. We also know that having divinity means the person has ichor flowing through them and we also know from conversations with Robert that Asterion no longer has his divinity.
2. Luke's Brother died on the January 28, 1986 Space Shuttle Challenger disaster. I base my theory on the the conversation you have with Luke when you give him time off he mentions a really difficult test that he and his brother needed for their dream job. I believe it is reasonable to assume that Luke and his brother were trying to become Astronauts based on Luke's love for the stars and the fact in Luke1 we see him in Cape Canaveral waiting to see the shuttle launch.
3. The Protagonists of the story is subconsciously bringing in gay Mythical creatures in to the Hotel. I don't have much to say other than how unlikely it is for Mythical creatures that also happen to be gay to come to the Hotel and become a part of the Hotel's Staff.
4. The Protagonist was influenced/ Possessed by Hades when Hermes was about to kill Argos/Nikos in Ch.18. I base my theory on the nearly rotten flower smell the Protagonist smells now this by itself could mean anything but Hermes mutters a name to himself which means someone he knows interfered and it stands to reason that Hades interfered to prevent Hermes from killing Argos/Nikos.
I would love to hear other peoples theories. I'm also open to hear if you disagree on my theories and why