Pretty badass, but I'm not sure what to make of the text-- is 命刃 a compound of some sort(めいじん perhaps)? What would that mean? Or is it some Chinese anachronism (Buddhist proverb, for example)?
Though I'm pretty sure the net effect is something along the lines of "I'll protect this place with my life!!", I can't figure out how this works well enough to make a good translation of it.
Oh god, now that you point that out, that should have been blindingly obvious. Thank you; I'm going to go lay about with Occam's Razor on my metaphorical wrists. orz
I will turn this life into a swordand protect this place!