The AI from the previous mission has some new code that will allow you to change the element of one of your powers and has such a place for you to test out these new powers. Head to the Broken Shillelagh and you’ll see an icon outside, which will transport you to another area, pretty much the same as the various training grounds you’ve visited already.
Your new power is the fire element for your Blast power, which works the same as the previous element, but now you can burn enemies with it. This is your introduction to different elements for your attacking Powers, with each one you get having three different elements (outside of DLC, which includes an additional two for each one). Once you complete the training, the mission will end.