Spontaneous combustion like what happened with Shishio is impossible. If his body temperature was rendered unnaturally higher, his brain should have boiled in it's skull.
Houji: Komagata Yumi...She was not always a fortunate woman, but she found happiness in death.
Kenshin: Where...Where is the happiness in death? If she was alive, she could know many kinds of happiness.
Yumi:(After Shishio stabs through her) I-I'm...so...happy. I could...I could be...it's the first time...in a fight...and I actually made a difference in the outcome of Lord Shishio's fight. I-I was always jealous of Sou...the boy, and Kamatari. For Lord Shishio, fighting is everything. But all I could ever do was take care of you. I was always...Yes...It always bothered me. But it's different now...P-Please win...this battle...Lord Shishio...Yumi's one step ahead...And I'll be waiting for you in hell...
Shishio: The weak shall become food for the strong! So die and let me feast!
Aoshi: The flow of time that led us all from the revolution to where we stand now, denied Makoto Shishio his victory, and sided with the Battousai. The times have chosen the person who deserves to live.
Seijuro: (About the Ama Kakeru Ryu no Hirameki) Even if you avoid the fangs of the dragon by soaring high, you will be drawn in by the fierce wind and shredded by it's claws.
Makoto Shishio doesn't die from the Amerakaku Ryu no hira Meki, he dies painfully from an overload of heat on his body, hence his blood evaporating, because of this, Kenshin doesn't break his vow. This would commonly be known as spontaneous combustion.
He must have believed that it was the "Sonata quasi una fantasia" Op.27/2 in C minor "Moonlight Sonata". Some loser web site must have gave him an over romanticised translation of it. Also, the Moonlight Sonata was Beethoven's 14th Sonata. So, he was badly mistaken
Just a note on the music thing. The piece being played is not Beethoven's 13th Piano Sonata. It is actually instead the second movement, or Adagio Cantabile from Beethoven's Piano Sonata No. 8 in c minor. The confusion is that it is OPUS 13. Meaning is is actualyl the 13th published work that Beethoven wrote. So Opus nubmer is 13, not the Sonata. I'm not sure where the person who originally posted this got that it was called "Midnight Blue." Beethoven's 8th Piano Sonata was alos known as the "Pathetique" sonata. The piece heard in this episode is actually the second movement from this sonata. Just wanted to clear that up. sorry. It's the Musicologist in me.
The music playing as Yumi protects Shishio is Beethoven's 13th Piano Sonata. Also known as Midnight Blue.
Shishio spontaenously combusts and finally dies.
Yumi is killed by Shishio when she begs Kenshin to spare him. He impales her on his blade to get to Kenshin, who has dropped his guard.
With the clue from Soujiro, Shishio break the Amakakeru Ryu no Hirameki... only to discover that all battoujutsu techniques of Hiten Mitsurugi Ryu have a second part to them...
Shishio was not superior to Kenshin, not by a long shot. Shishio had Kenshin fight his men in deadly duels one by one. A series of battles that were designed to weaken Kenshin. It was also in Shishio's interest since his lover would witness Kenshin's attacks and inform Shishio. But in the end, the best man won, even when it looked hopeless, ( a Yugioh theme ) his bond with his friends and his master and Kaoru, his love even though she's the same age as Tome, his first love, was able to defeat Shisio with out breaking his vow to never kill again.