Rurôni Kenshin -Meiji kenkaku romantan1996

Seijuro Hiko:
Because you've slain so many people, you don't even value your own life. That's what allows the manslayer's heart that lies deep within your true heart to take over your soul. Even if you use the power of that manslayer for a self-sacrificing purpose such as protecting those you love or the weak, it's still only one tiny pebble in the never-ending river of time. Live on, Kenshin. That way you'll be able to use the Amakakeru Ryu no Hirameki as you please and you'll never again lose to the manslayer within you.