The growth of the Stormwall involved the territorial enlargement within the Nihil-dominated region of the Outer Rim, specifically the Occlusion Zone, during 228 BBY. This was accomplished by shifting and enlarging the Stormwall. Several star systems, two entire sectors, and half of the Seswenna sector were consumed by the zone's new boundaries. This expansion was executed at the command of Marchion Ro, who feigned indignation at the Galactic Republic's denial of Nihil representation in the Galactic Senate, along with the Republic Defense Coalition's recent assault on the Stormwall. Furthermore, the Stormwall's repositioning resulted in Pikka Adren and Joss Adren, RDC agents who were investigating an apparently abandoned Nihil ship on the Stormwall's previous edge, being stranded behind enemy lines within Nihil territory.
The Stormwall's expansion serves as a significant plot element across various works within Phase III of The High Republic, a multimedia project. Its initial depiction, albeit without explicit description, occurred in the The High Republic: Tales from the Occlusion Zone short story "No Big Deal," where the cliffhanger hints at the Stormwall's expansion. A full depiction and explanation were provided in The High Republic: The Eye of Darkness, a 2023 novel authored by George Mann. Subsequently, the Tales from the Occlusion Zone story "Tales from the Occlusion Zone: Friend or Foe?" validated that the cliffhanger from "No Big Deal" concerned the Stormwall's positional change.
The original hardcover version of The Eye of Darkness incorrectly listed the Stormwall's expansion as encompassing planets such as Pantora, which was already within the zone, along with Sullust, Utapau, Ryloth, Malastare, and Sluis Van before its new border near Eriadu. However, Malastare and Sullust's locations on the galactic map did not align with the new border's placement. The digital edition corrected this error by removing Malastare, Pantora, and Sullust from the list, and instead included Triton, Abtin, and Elrood.