If you look at the sword you'll noticed the sword's material downgraded from iron and gold (I) to iron (II), bronze? (III), stone (IV) and wood (V). This is most likely a nod to Jīnyōng's novel "Xiào ào jiāng hú". In this novel there is an invincible, undefeated swordmaster from the past. He first used a good sword at first, when time pass he then change his sword to ordinary sword, heavy metal sword, bamboo sword, then using bare hands in a sword fight, seeking someone to defeat him to no avail.
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