Hokuto no Ken Episode 82
Kenshiro thinks about Souther, another member of the Nanto Roku Seiken, who was the master of Nanto Ho'oh Ken (South Star Phoenix Fist). He remembers how he fought against Souther and eventually defeated him, after working out his secret. Ken also thinks about the last remaining member of the Nanto Roku Seiken, who he has yet to meet, and wonders who he could be. As night turns to day, Kenshiro walks away from Ryuga's castle.
In the manga...
-This episode is filler and does not happen in the manga.