"One Punch Man" episode 12 is entitled "The Strongest Hero."
Watch "One Punch Man" episode 12 here. This week's installment, and the last episode of "One Punch Man" season 1, opened with an epic fight scene between Saitama and Lord Boros.
"One Punch Man" episode 12 showed Saitama's serious face while he was battling Lord Boros. There was one scene where the two fighters generated a super powerful punch that cut off the alien monster's arm.
Lord Boros was amazed that, even though his true powers have been unleashed, Saitama was still able to keep up with him. "You're pretty strong, too," the hero-for-fun replied.
Meanwhile, the class S heroes are still trying to destroy the alien spaceship from the outside. Tornado used her psychic powers to send debris towards the vessel.
As previously mentioned in the "One Punch Man" episode 12 spoilers, Genos was warned by a fellow Class S hero to be careful and stay away from Metal Knight.
"One Punch Man" episode 12 showcased Lord Boros and Saitama's full powers which resulted to an epic fighting scene with the show's theme song being played in the background.
Lord Boros went on a monologue about how his species has developed regenerative abilities that is instrumental for him to defeat Saitama. The hero-for-fun, who detests long monologues, told him to shut up. Lord Boros got angry and fired at Saitama.
Afterwards, one of Lord Boros' attacks sends the series protagonist to outer space. There was a funny scene in "One Punch Man" episode 12 where Saitama held his nose when he realized that he was on the moon.
He was able to come back and fight a weakened Lord Boros. Saitama packed his iconic one punch to Lord Boros and followed it up with his Consecutive Normal Punches.
Saitama's killer final move is the Serious Punch which destroyed the spaceship and the marble thing inside Lord Boros' head. The alien monster admitted that Saitama was too strong for him.