'One Punch Man' season 2 spoilers: Saitama to taste his first defeat at the hands of Lord Boros?

Saitama might face his first defeat when "One Punch Man" returns for its second season.

Season 1 left off with Saitama coming face to face with Lord Boros, the powerful leader of an alien group known as the Dark Matter Thieves. Lord Boros gave Saitama a tough fight, and even though the hero defeated him, he didn't end up dead, which is unlike most of Saitama's previous opponents.

As a result, fans speculate that the evil ruler will come back to battle it out with Saitama again in season 2. Lord Boros is expected to give Saitama a tougher fight, with some even believing that Saitama might face his first defeat when he grapples with Lord Boros. He will reportedly arrive when Saitama is at his weakest, easily beating the lead character.

While Lord Boros has been suspected to be one of Saitama's main enemies for next season, other possible bad guys have also been named. Rumor has it that Amai Mask will attempt to challenge Saitama when he begins to show his darker side. Fans can recall him as a friendly character who appears to fall on the good side, but it is believed that he will show a different side of him in the sequel as he becomes a major threat to Saitama.

Meanwhile, reports say that the story could go another way and not explore Saitama's downfall. If the original manga series is to be followed, the plot picks up with "The King Arc," which will then be followed by the "Human Monster Saga."

The show's first season aired in Japan from October to December 2015, spanning a total of 12 episodes. The anime was first released for English-speaking viewers on July 2015 through Adult Swim's Toonami Block.

An official release date for the second season of "One Punch Man" is yet to be announced.