Supplies: 125
Power: 5
Monthly upkeep: 30
Psionic Gate
Requirement
Supplies: 200
Power: 4
Monthly upkeep: 50
Additional Function: Advance research projects
The Shadow Chamber unlocks new research projects that usually pushes the narrative of the game. Unless you want your soldiers to be sent to their death, take time before you build this facility because you will needlessly advance the story while you are extremely unprepared.
In fact, do not proceed in Skullmining the CODEX (which is available after researching this on Proving Ground after performing a Codex autopsy), because you will trigger an event that will lead you to fight an Avatar. Unless you have a well-trained Psi Operatives, do not proceed with this and just wait to have a skilled Psi Operative (or multiple Psi Operatives) to be available in a mission.