Thay group I presume is the team doing the vex research in the grimoire. Dr Shim and a couple of others. Two of them are referenced as being lovers. My presumption is that they looked into the mind of a vex, went mad and locked themselves in the archive to die from inaction. If you read the cards they talk about how they can't figure out if they are real or not. Dunno where the hands and feet come into it.