Evangelion Unit-04 (Rebuild)

Evangelion Next Gen Testbed-04 exists in the films only as a report. Developed in the United States as a trial platform, the unit is mentioned in the second film and never depicted, its appearance left unspecified even in the Complete Records Collection companion book. Where the television series classed its Unit-04 as a Production Model, the Rebuild continuity labels it a Next Gen Testbed, echoing the Test Type designation from the original series Proposal.

Its one documented feature is its purpose: had the experimental engine been finished and brought online, Evangelions would have gained dramatically longer operational time.

The unit hosts the installation trial of an experimental S² engine at NERV's second branch, sited in the southwestern reaches of Canada. A mysterious failure of that engine erases the Eva, the branch, and everything within a diameter of more than eighty kilometers in a blast resembling a smaller-scale Second Impact, complete with an enormous cross of energy climbing from the site into space. The disaster forces the transfer of Unit-03 to Japan, setting the stage for the Ninth Angel incident.

Unit-04 is one of only two Evangelions missing from the Neon Genesis sequence of Thrice Upon a Time, in which the Spear of Gaius destroys every unit; its design remains unknown alongside that of Unit 8+2. An early CG layout shared by Studio khara in 2023 shows the scene once included a Unit-04 rendered as a silver recolor of Unit-03, matching its treatment in the original series.

No pilot is ever identified, and the unit belongs to NERV's second branch rather than the Tokyo-3 roster. Its afterlife is merchandising: a 2017 Revoltech figure and a 2022 Bandai RG model kit both recolor Unit-03 in silver, phantom releases whose designs carry no official standing, with the Bandai kit even omitting the Next Gen Testbed portion of the official Japanese name.