Ahead of the release of Stranger Things' fifth and final season, the show's VFX team has detailed how they rebuilt the villain Vecna and the series' otherworldly dimensions for what creators Matt and Ross Duffer called a "mega movie" finale. VFX supervisor Betsy Paterson told The Hollywood Reporter that the production's expanded budget allowed for far more shots than a typical feature film, enabling an elaborate send-off for Hawkins' characters as they mount a final battle against Vecna, played by Jamie Campbell Bower.

The team continued to lean on practical effects enhanced with digital work, building tactile sets such as the Upside Down's membrane wall and a liquefying room at Hawkins National Lab so actors including David Harbour, Millie Bobby Brown, Natalia Dyer and Charlie Heaton had real surfaces to interact with. While the Upside Down's look was already established from earlier seasons, the new realm known as the Abyss, or Dimension X, had to be designed from scratch; after ruling out shooting in a real desert for logistical reasons, the crew used extensive scanning and reference photography to give the CG landscape an authentic, grounded feel.