The conversation with Viconia

This now seems to imply that the Githyanki fought the Absolute over the artefact, and that both parties were so weakened (or busy) that Shadowheart could snatch it sneakily.
But that makes even less sense, if she was then caught and tadpoled on the Nautiloid.... unless indeed the emperor was also aiding behind the scenes, still as mindflayer on the nautiloid. Tadpoling Shadowheart and hiding the artefact on her.

[Linked Image from i.imgur.com]
[Linked Image from i.imgur.com]
[Linked Image from i.imgur.com]
[Linked Image from i.imgur.com]
[Linked Image from i.imgur.com]
[Linked Image from i.imgur.com]