There's surprisingly little information on this card. So I figured I would ask here.
From what I understand, there are three ways to get this card. Farm Syrcus Tower, Farm World of Darkness, and buy Mythril Packs. I'd rather farm, but I suppose it'll be good to have something to buy after I get Fenrir and Cloud. And Zidane.

Anyway, which has the higher drop rate? And what is the drop rate? I'm seeing many people say they have had quite a few drop, and I see many people say they never see it. So I'm torn.
And as to where it drops, I assume they're talking about World of Darkness. But it's not explicitly stated.