SCP-[...] is to be contained within a Faraday cage testing chamber measuring 10m x 10m x 5m at Research Site-██. The chamber should be equipped with shielded observation windows and remote monitoring equipment. Access to SCP-[...] is restricted to personnel with Level 3 clearance or higher, and requires written authorization from the Project Lead.

Any testing with SCP-[...] must be conducted with two D-Class personnel. Both D-Class must be psychologically evaluated before testing, and any history of dissociative identity disorder, psychosis, or other relevant mental health conditions will disqualify them.

Following any testing, both D-Class subjects (or one of the D-Class subjects if one dematerializes) are to be immediately quarantined for a period of no less than 72 hours. Psychological evaluations and neurological scans are to be performed daily during the quarantine period. Any anomalous changes in personality, behavior, or neurological function are to be reported immediately.

SCP-[...] consists of two components: SCP-[...]-1, a modified full-body scanner, and SCP-[...]-2, a custom-built computer system connected to the scanner. The scanner itself is unremarkable in appearance, resembling standard medical imaging equipment. SCP-[...]-2, however, displays several anomalous modifications, including an unusually complex wiring configuration and components of unknown origin.

When a human subject (designated SCP-[...]-A) is placed within SCP-[...]-1, SCP-[...]-2 will initiate its boot sequence. Upon completion, the system displays a user interface featuring a live video feed of SCP-[...]-A and a prompt instructing the user (designated SCP-[...]-B) to connect a provided electrode to their forehead.

Once the electrode is connected, the interface displays a graphical representation of "personality constructs" associated with both SCP-[...]-A and SCP-[...]-B. These constructs are displayed as draggable icons within separate boxes labeled with the subject's designation. The number of personality constructs varies between individuals; however, multiple uses of SCP-[...] on a single individual can lead to the manifestation of multiple constructs, and those who have never used SCP-[...] will only have one construct. The user interface allows SCP-[...]-B to manipulate these constructs via a drag-and-drop interface. The following outcomes have been observed:

• Transfer of Construct(s) to Target: If one or more personality constructs are transferred from SCP-[...]-B to SCP-[...]-A, and the original box for SCP-[...]-B is left empty, SCP-[...]-B will physically dematerialize, and their mass will be transferred to SCP-[...]-A. SCP-[...]-A will then exhibit the personality traits, memories, and skills associated with the transferred construct(s), effectively becoming a composite of their original personality and the transferred consciousness.
• Transfer of Construct(s) from Target: If one or more personality constructs are transferred from SCP-[...]-A to SCP-[...]-B, and the original box for SCP-[...]-A is left empty, SCP-[...]-A will physically dematerialize, and their mass will be transferred to SCP-[...]-B. SCP-[...]-B will then exhibit the personality traits, memories, and skills associated with the transferred construct(s), effectively becoming a composite of their original personality and the transferred consciousness.
• Partial Transfer: If one or more constructs are transferred between subjects, and both subjects retain at least one personality construct after the transfer, neither subject dematerializes. Instead, the designated personality constructs are moved from the original host to the receiving host. Both subjects' personalities will thus be altered, based on the constructs that now reside within each host.

Subjects with multiple personality constructs within a single body report experiencing a shared consciousness. A unanimous voting system determines which construct controls the host body at any given time. Non-dominant constructs can communicate telepathically with the dominant construct, often manifesting as auditory hallucinations resembling voices emanating from telephone speakers. The dominant construct can also communicate back to the non-dominant constructs through internal monologue. All personality constructs within a single body share an interconnected communication network.

SCP-[...] came to the Foundation's attention following an incident at Site-██ involving Researcher Dr. [REDACTED], who, through prior experimentation with SCP-[...], successfully rescued two colleagues (Researcher Dr. ██████ and MTF Agent ██████) from a lethal cognitohazard by transferring their consciousnesses into his own body, now possessing three distinct personality constructs (Dr. [REDACTED] himself, Dr. ██████ and MTF Agent ██████).

It has been determined that Class-C Amnestics are ineffective in suppressing or erasing transferred personality constructs. This suggests that the constructs represent a fundamental alteration of consciousness rather than a mere alteration of memory. Further research is required to determine the precise nature of these constructs and the long-term effects of SCP-[...].