Jinei was never called the Battousai in this episode, rather he was known as a stray Manslayer.
Actually the term "Manslayer" was not cartoon network's idea but Anime Works.
Jin-e is not a "battosai", but a hitokiri, which means assassin in Japanese, or as Cartoon Network puts it, "man slayer".
Battosai is the nickname given to Kenshin because he has mastered all aspects of the battoujutsu techniques, that of starting the sword in the sheath to increase the speed of the attack.
Sanosuke: Those eyes... he's too dangerous.
Kenshin: I'll deal with him.
Kenshin: Why are you here?
Sanosuke: I won't let you hog such a big fight to yourself.
Kenshin: It's not a fight...
Kenshin: The man Kurosaga, he must be a manslayer from the revolution like myself, that he is.
Kaoru: Oh, you're the police chief.
Sanosuke: The police chief?
Sanosuke: It's not food from a strange land...
Kaoru (While throwing foods at Sanosuke): If you have any complaints, then don't come here!
Kaoru: Oh, Sanosuke is drooling all over because it's so good! Just kidding!
Sanosuke: It's disgusting.
Kaoru: Oh, Kenshin.
Kenshin: Huh? Wha! Ow! (sword falls and slices thumb open)
Kaoru: I... found you.
Kenshin: She's scarier than Jinei she is!!
Kenshin: The murderer called Kurogasa he must be one of the Manslayers left over from the Revolution, just like myself. Even though it has been ten years into the Meiji era, his heart is still obsessed with the smell and color of blood. A man who cannot stop killing.
Kenshin: Nikaidou Method. Shin-no-ippou, another name for the spell of frozen terror. As I suspected it was you after all. I heard rumors in Kyoto during the Revolution of one who could use Shin-no-ippou and paralyze victims with the pounding energy emanating from his eyes. The stray Manslayer, Jinei Udoh.
Jinei: That wasn't any fun. You are nothing compared to the Battousai of the Revolution whose name froze the blood of men. A Manslayer who stops slaying for ten years. You should realize how obtuse your swordsman spirit has become.
Jinei: I'll give you one day to prepare yourself. Go ahead and search your soul. I know you'll find him. Revive the Manslayer within you. I want to kill the legendary Battousai from the Revolution.
Kenshin: Ms. Kaoru!
Jinei: I assume this girl is your woman, Battousai! (Evil laugh)
Jinei: Show me your anger! That will bring back the Manslayer that you once were! Hate me as you never hated before! Bring back Battousai the Manslayer! (Evil laugh)
Kaoru: Oh Kenshin, I found you.
Kenshin: She's scarier than Jinei, she is.
Sanosuke: I guess selfishness and love go hand in hand.
Original Air Date: February 14th 1996
Nobuhiro Watsuki was supposedly reading American comics at the time he created Rurouni Kenshin, particularly the X-men and Spawn. This can vaguely be seen in the fact that Jinei's headgear is quite similar to Gambit's in the X-men.
Kurogasa, Jinnei's nickname means Black Hat.
Jinei Udoh was originally based on one of the four real hitokiris in the Bakumatsu era, named Okada Izô, although the author admits that Jinei ended up nothing like Izô.