From the console, or another virtual terminal, I launch X11. This is in Free BSD. I cannot return the display to any other terminal afterwards. By using the ctl-alt-F1 key combination, for example. Using that key combination seems to direct the keyboard input into the shell still running on that console, so I can launch another xterminal in the X11 controlled display, or shutdown gracefully, all without seeing what I am typing.
I can kill X11 from the display, or merely kill all apps on it, and even then cannot get the display to echo the output of the keyboard, from any virtual teminal or the console.