NECROVALLEY DROPPED. I was farming Ishizu level 40 for my 3rd gravekeeper's chief and this card dropped. I checked the forums and apparently a handful of people have also managed to get it. It's a secret rare drop that isn't listed on the card rewards. It comes in an obsidian/onyx black pack.
I put it in my GK deck but it's not that consistent since I only have one copy. But I am so thrilled to get my hands on it.
Anonymous
Gem Hunter