I'm gonna say it's Junon and Shiva Materia
In a land of darkness, - the plain near Junon is dark
Here I reside, - the town reside there, at the dark plains
Though you can approach me, - you can come to this place
I've nothing to hide. - the town seems to be out of hope and have nothing to care
As fighting forbidden, - fighting forbidden, shinra caused that
I claim they're just fake, - this probably talking about Shiva, Priscilla, dolphin or the monster that attcked you at beach.
But to get them from me, - The item is Shiva Materia
I give, what you take. - The party have to used CPR (?) and beat the monster for the itme above.
