Looking for informations about that weapon!

[Natsuma]

Hello there,

I just saw this amazing sword in the Auction House and I'm really looking for informations about it...
Especially how to get it :D

Here is the screenshot:

[SPOILER-BOX]
http://img688.imageshack.us/img688/3292/pso20120629200041001.jpg
[/SPOILER-BOX]

It has ~550 ATP FYI.

[Priest]

It drops in Hard cave exploration, that's all I know. Don't think you can equip it at lvl 30 tho.

[Emery25]

Oh baby now thats a beauty.