This one starts pretty good, but goes downhill for more reasons than that. For one thing, about halfway through it starts to drag on and on, which hurts it a lot, and nothing anyone does goes anywhere. What little happens is resolved easily, too. The slash compounds that, especially because suddenly everyone does it, with Aerith and Tifa hooking up, Cloud's anus turning into a clown car, and so on, but that's far from the only issue.

But I'll third Evolution. Raziel13 does some good stuff, too. A lot of his works suffer because of the shipping*, but Whispers of the Gods is great anyway. I'd ignore his pure fluff stories, though.

*Which isn't a problem in and of itself, but rather because it's either a foregone conclusion or because he skips all efforts to develop the relationship and just has Lightning and Fang together**.

**Also, they impregnate each other somehow in some of his stories which is, uh, what?