So for your characters, I'm guessing you're taking the approach of them needing the elements around them to use their elements? Cause for these elements you don't really need the element around for them to control and manipulate them, they can conjure them out of thin air if needed. Kind of like Hasuno did at the start of the roleplay, when she created a ball of water to move around. Which is where the Soul comes in, one uses their own soul to conjure the element they control into reality. While using the mind and body to control and manipulate, and imagination to allow them to command the elements to bend to their will.