"Once Upon A Time" Season 5 will be set in the underworld, and Emma (Jennifer Morrison) and her friends will face their toughest opponent yet.

Entertainment Weekly exclusively reported that "Ally McBeal" alum, Greg Germann, will play the role of the god of the underworld when the show returns next year. Executive producer Adam Horowitz confirmed the news, explaining that the character is inspired by both mythology and the Disney movie, which is why they decided to create their own version of the character.

It was reported that Hades will appear in the mid-season debut of "Once Upon a Time" Season 5, which is also the 100th episode of the show. Horowitz also revealed that Hades is connected to another character in the show.

Some fans speculate that considering Hades is a villain, he may be related to the evil queen Regina (Lana Parilla). However, the showrunner did not reveal the character that's connected to the new villain.

Meanwhile, it was earlier reported that Emma and her friends will be seeing some of the past charters returning for the show's 100th episode like Cora (Barbara Hershey), Cruella de Ville (Victoria Smurfit), and Peter Pan (Robbie Kay). The 100th episode is also said to introduce the new cast members, "iZombie" star Jonathan Whitesell and "Hannibal" alum Kacey Rohl, who were cast as Hercules and Megara, respectively.

In other news, iDigital Times reports that Belle, who is played by Emilie de Ravin, might be pregnant in the show after it was earlier confirmed that the actress is pregnant in real life. With this, many speculate that she might become pregnant in the rest of the season or she won't be appearing for the second half of Season 5, considering that everyone is in the underworld.

"Once Upon a Time" Season 5 will return on ABC on March 16.