"Fear not, defeated one.
A new light comes forth to protect you..."
Also went over the previous thing. I think the second line is wrong in context. Judging from how "ga tame" is used in the latest bit, "Nanji no chikara ni naran ga tame" strikes me as "in order to become your strength," and "miru ga ii" appears to be idiomatic - like "yattemiru," "to try to [do something]".
Charon: You cannot yet cross this river, mortal.
For a light yet shines upon you as your protector.
That light has taken form upon this riverbank,
seeking to become your strength.
Now, return from whence you came.
Stand once more, and be reborn with the power of light...
I would Olde English it up a bit, but I'm not sure how far to go before it'd become silly. ("The light hath" would be a good place to start, but where would it stop?
XD) Also, technically
the other translation of the first and final lines are more accurate, but I think my versions sound a little more suitably dramatic? :3EDIT:
Never mind on that second part. Pretty sure I'm right about "to become your strength" but not so much about the rest. ^_^;