hey,
what you have to do is.. if you have not already done this is just around the corner
opposite the steel door you find the professor on what looks like one of moneybags
platforms for his shop what you must do is press (Y) and he will tell you... that you need
40 light gems to power the super charge gadget.. so try your hardest and get all the mini
games including hard done, try just exploring the map.. and when you have came to that
point.. go back the proffesor in the cloudy domain and he will unlock it for you.. then
you use your horn dive to break open the door... it may seem confusing but if you are
confused tell me a bit more about your up to date problem's! thanks bye!!