Thread:Lord Hyōga/@comment-26504521-20150822224459/@comment-4576906-20150822225130

That's a really ambiguous point in the third movie. He was mortally wounded by Ryūkotsusei and Myōga says this is what ultimately caused him to expire. However, Myōga was not with him during the final battle with Takemaru. So you have Ryūkotsusei, the burning castle, and Takemaru that could have actually slain the Inu no Taishō...however, it seems unlikely that a mere human or a burning roof would actually be able to cause the Inu no Taishō to die; in light of that, and the weight of canon, I would say he succumbed to his wounds from the fight with Ryūkotsusei.