Hokuto no Ken Episode 68
Souther's secret was that he has dextrocardia situs inversus totalis -so his pressure points are reversed. Kenshiro hit a point on him that makes his arm bulge up, but he is strong enough to stop it from exploding, and then uses the ultimate move of his style -Nanto Ho'oh Ken Ougi: Tenshou Juuji Ho (South Star Phoenix Fist Secret Technique: Heaven Soaring Cross Phoenix). This lets him move so fast he appears to go through Kenshiro, and slice into his shoulders, without him being able to hit him back.
This works a few times, but Kenshiro eventually counters it with a secret technique called Tenha Kassatsu (Heaven Breaking Impalement), where he sends forward a wave of his touki, and allows him to hit several of Souther's pressure points without him having to make physical contact. Souther tries to attack Kenshiro again, despite his injuries, but is ultimately defeated and finished off with the Hokuto Ujou Mosho Ha (North Star Humane Fierce Flying Rip), a technique that will kill him, but does not cause any pain.
Kenshiro tells Souther to remember the warmth, and this makes the Holy Emperor remember his time as a child, with his beloved master, Ogai. Kenshiro walks down the mausoleum, which begins to crumble. As he is surrounded by Bat, Lin and the other kids, Toki realises he has nothing left to teach Kenshiro. Raoh sees one of his enemies is dead, but he cannot grasp the heavens before defeating Toki and Kenshiro, the only two who stand in his way now. He tells Toki they will meet again before leaving.
In the manga...
-When Souther uses his secret move for the last time, he starts stabbing at Ken rapidly in the anime, but this was not in the manga. In the manga, when Souther heads towards Ken for the last time, he never gets to try and attack, as Ken just starts rapidly punching him before he gets the chance to do anything.
-The scene at the end where the kids surround Ken was not in the manga.
-Once again, the art in this episode isn't very good. Better than the previous one, but still lacking compared to the average episode in the series. Lin in particular is drawn poorly.
-The start of this episode has a brief recap of what happened at the end of the previous episode, but there is one difference -in the original episode, when Souther started to slash Ken's face, you actually saw Ken in the shot. However, in the recap in this episode, they zoomed it right in so you can only see Souther -did someone find it too violent originally or something?
Near the end of the episode, Lizo (last seen here) makes a cameo appearance, but he has a different outfit and colors then before. (And I somehow doubt he had any time to get changed between episodes.)