Rurouni Kenshin: Meiji Kenkaku Romantan

Synopsis

Shishio doesn't believe that Kenshin understands the laws of nature, philosophizes about the survival of the fittest through chaos and not just a worthless mirage of peace. Shishio then uses the Guren Kaina attack, the second of his Secret Sword technique, giving Kenshin a concussion. Saito suddenly busts through the door, using his Gatotsu First Stance, executing the Ishiki attack. However, Shishio is protected by a metal plate in his forehead. After trying the rest of his Gatotsu stances, Saito soon gets knocked out by Shishio. Even Sanosuke attempts to attack Shishio, but to no avail. It is then that Aoshi appears to engage in combat with Shishio.

(Source: Wikipedia)