The Demon Heart Sword Slave was certainly a formidable figure who comprehended the extreme Sword Dao in life. Due to certain reasons, his sword heart was polluted, and after descending into demonic transformation, he lost all memory except for the Sword Dao, becoming a Sword Slave.
To have driven a Great Dao to a state of insanity, it's imaginable that such a Sword Slave, while alive, must also have been an unparalleled figure in the Sword Dao. Abandoning everything outside the Sword Dao to become a Sword Slave, though a descent into madness, results in an even more extreme and powerful control over the Sword Dao.
Sensing the aura of the opponent, Guding could imagine that even a powerful sword cultivator like Radcliff, when cultivated to the same realm as the opponent, might not possess the same mastery over the Sword Dao.
