Athene's Unholy Grail not in this patch.

Current PBE Shot of AHG

Despite it's appearance on the latest PBE build, Guinsoo  has confirmed that the new item Athene's Unholy Grail will not be added to the game in the next patch. This isn't really shocking though, considering it's absence from the Patch Preview's section about Caster items.

Athene's Unholy Grail will not be coming next patch, but look for it soon.

- Guinsoo, Game Designer, via the official forums.