The Stone Swordsmen were members of the Stone Army. They had an appearance similar to that of the Stone Scouts, but with full-sized legs capable of motion, as well as red, jagged shoulder armor, and blue facial markings. As their name suggests, Stone Swordsmen usually wielded black katanas, as well as a black-and-red buckler in their free hand for added defense.
The Stone Army are revived by the venom of the Great Devourer and attacked the Serpentine. They were freed, and started destroying the City.
A Stone Swordsman brings in a box of Dark Matter and said they uncovered more Dark Matter, but at the expense of losing many Warriors.
When Garmadon asked for the Army to gather, several Swordsman attacked Wu, but Lloyd and Misako trapped them. Later, they spotted Zane and tried to capture him, but they escaped and started pursuing them to the Temple of Light.
The Swordsmen help build the Garmatron. When Cole kicks a Scout off the platform, the Army attacked the Ninja. Eventually, they tried to stop the Ninja from returning the Helmet of Shadows to its perch, and succeeded. They kidnapped Nya as the rest of the team falls off a cliff.
Two Swordsman restrained Nya and helped Garmadon infect her with Dark Matter. A Swordsman and Scout refills the cannon when Garmadon and the Overlord requested it. After a brief battle, the Overlord created a portal for the Army to go to Ninjago City.
The Army prepare to attack the Ninja, who were actually diverting their attention away from Lloyd. When Nya got Lloyd out of his mech, the Army attacked him, but the Ninja went to save him. Just when they were outnumbered, Dareth dons the helmet and commanded the Army to go after the Overlord.
While Dareth was talking on the microphone during the Day of the Departed concert, he mistook the Stone Warriors as costumes. After Dareth realizes they are real, they chase him into the museum. He found the Helmet of Shadows and ordered the army to take on Kozu.