Hmm... poems don't translate well at all I'm afraid. I can translate it (with a bit of tweaking) but it will lose all it's sense of poetry, rhythm, etc...
Chomh dorcha leis an Mhuir Mharbh (as dark as the dead sea)
Chomh neamhbhásmhar le sí* (as immortal as an elf*)
Chomh fuar le h-iolar (as cold as an eagle)
Chomh daortha le príosúnach (as doomed as a prisoner)
?????? (I don't understand this part "Legend like a myte")
Fiachtar le naimhde (hunted by enemies)
Agus tagtha suas leis an t-am atá thart go luath (and caught up with the time that is finished** soon)
Níl aon bealach amach (there's no way out)
Níl ach bealach isteach (there's only a way in)
Hmm ok but thanks.It was just something I came up with directly to a story but thanks
*There are no 'elves' in Irish/Celtic tradition, only the 'sí' or fairies. The elf is from Germanic tradition, I think.
** There is no word for the past in Irish - you have to use a phrase, such as the old-times, that times that are over, the time that is spent