The rune word sword was almost indestructible, at least breaking a rune word weapon before its disintegration was unheard of. Frankenstein had no choice. He could only attack with the back of his rune word sword.
He wasn't skilled in the sword. His instincts just knew to smash things with objects.
You couldn't force a law-defying wizard to learn sword skills, especially one that only had battle instincts. Not all law-defying wizards were Abel, after all.
Frankenstein only remembered the command his master gave him to keep the enemy's corpse intact. After he froze the mad knight with the ice pole, he viciously smashed with the back of his rune word sword.
Although Frankenstein did not have many close body fighting skills, no one could underestimate the strength of an ancient puppet. It was not something even a mad knight could withstand.
Blood gushed out from the mouth of the knight. His internals was badly injured.