The Organyx

The Organyx is a space between Valhalla and the portal in Etro's Waterfall.

It is said other portals would have their own 'Betwixt and Between' between them and Valhalla.

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Much like everything in the Barq region, Organyx is a reference Lightning Farron. The Organyx is her ultimate gunblade in Final Fantasy XIII, and thus may also be the name of her Gunblade she wields in Valhalla, although this is not confirmed.