If Hypno were to ever recieve a cross-Gen evolution, I'd like it to be Psychic/Ghost. The move Nightmare is a Ghost and Ghost is the most creepypasta Type for the original creepypasta mon. And I like this more than just slapping Dark on—Ghost is more nuanced than that, and despite how the fandom portrays it, I like to think Hypno are not actually sinister. They are just odd, creepy and difficult to understand.
Its design could incorporate aspects of spirit mediums to justify Ghost a little more. Ghost also has shadow-based moves that fit Hypno well because dreams are immaterial and take place largely in the shadows of the subconscious mind.
Dunno the name tho. What's the logical progression from drowsy -> hypno -> ???