Lol! Well, idk about the Disney universe lol. It seems Morpheus is the one responsible for dreams and sleep and his little brother Phantasos is the god of nightmares. I remember in the Long Nightmare episode Phantasos acted sorta like Hades does with Zeus (Zeus even brought up that fact with Morpheus in a flashback to when the gods first received their roles). He wanted his older brother’s job, so he caused people to have bad dreams so Morpheus would get the blame for not doing his job right (because before Phantasos there was no such things as bad dreams) and Phantasos would pretty much either suggest himself to be the new god of sleep and dreams or Zeus would automatically elect him such. That obviously didn’t work out, but Phantasos got a good job out of it anyways by becoming god of nightmares lol.
But yeah, with all that being said, I can see Hades and Phantasos being friends actually. They both can kinda relate to each other lol. I mean, Hades did laugh at his idea of people having embarrassing dreams of showing up naked at school lol (not in a bad way of course, it was just a funny idea lol to him and everyone else), so yeah, I can see them being friends, but at the same time I can also see Hades thinking that he’s too whiney and annoying about wanting to be god of sleep. He acts like a spoiled child while Hades comes off as more menacing and bitter with his brother. He’d be all like “Trust me, I tried pulling that ‘gimme gimme’ stuff with my older brother when I was still a kid and it didn’t do a thing for me. Rookie move.” Lmao but yeah, I don’t think Hades really associates with dreams in the Disney universe lol