thank you for the feedback! sorry about that, it was something that we thought would cause a problem for people. (for anyone else that runs into this) you can only fight in spirit form, but can only use the keys in living form. all items in their use form have to have a left click hold, then a right click to use. we will update the control description on the page. then in game after the jam.
thank you again for pointing this out
-Lizabet