The Showtime serial killer drama has been picked up for a seventh and eighth season.
"I think [in the new episodes] I'll be challenged to incorporate some very new and powerful dynamics into Dexter's world," Hall told What's On TV. "To be honest, it's difficult for me to foresee an entirely happy ending for the character."
Hall added that he is keen to play a lighter role once Dexter comes to an end.
"I'd love to do a comedy where nobody died," he admitted. "I'm aware that there's an inevitable residue of Dexter that will be on me.
"But at the same time, when [HBO drama] Six Feet Under was on, everybody thought I was a gay funeral director. I guess [Six Feet Under character] David Fisher was Dexter's first victim."
Showtime president David Nevins previously hinted that Dexter could continue for a ninth season.
"[Season eight] is the likely endpoint, but I'm leaving open the possibility that plans could change," he said in January.
Dexter returns to Showtime on Sunday, September 30 at 9/8c.
> Dexter Michael C Hall: 'All bets are off in season seven'
Watch a trailer for Dexter's sixth season below: