Overcome with rage and despair, Jack killed the mutated Rams, only to stare in horror when he saw what he had done. After he foiled Jack's attempt to use the last of them and destroyed it, Aku mutated three innocent rams into monsters for Jack to fight. To some extent, what the Spartan King did goes against what the African Chief said: in Young Jack in Africa, the Chief told Jack that only he could use it, though it is possible that the Chief meant against Aku, as only Jack and his father have used it on Aku himself.Īt some point over the next 50 years, Aku began to actively destroy all of the world's time portals. It was also revealed that The Emperor had used the katana to kill the bandits that threatened him and his family after they refused to leave them in peace ( Episode XCIV), though it is possible that the Emperor used a normal katana against the bandits, as in the first episode the holy katana was kept in an altar. Very few characters other than Jack used the katana in the series, most notably the King of the Spartans, after his own sword was broken and Jack threw him the katana to protect himself ( Episode XXV: Jack and the Spartans).
However, that property appeared to apply only to biological lifeforms and not to robots, as Jack, when he was infected by Aku's essence and became Jack-Aku, either killed or grievously harmed an innocent robot with the katana, but appeared not to be able to kill the Lizard Monks, whom he struck with it and only rendered them unconscious ( Episode XLIII: The Aku Infection). Instead of stabbing Jack, the katana simply struck Jack's chest without causing any harm at all ( Episode XXX: Jack and the Zombies). That was first demonstrated on one occasion where Aku took the katana and attempted to kill Jack with it. The katana could only be used for good in the hands of evil, it could never harm an innocent. Enough strikes with the katana essentially negated Aku's ability to regenerate from his wounds, at which point further damage could severely weaken his powers or seal him inside the katana. Its divine nature was capable of inflicting burning wounds to Aku, which were very difficult for him to regenerate from. When Aku invaded the Emperor's domain, the gods Odin, Ra and Rama forged the katana from the power of righteousness extracted from the Emperor's spirit.