Depending on what kind of skull u got, u could save & quit, then turn off the Xbox. The only time I was stuck like that was when I saved while turning invisible with a ceartin skull(forgot the name) with the spartan.
yea well turning invisable whith the spartan is one id probly like to keep . and the only way iv herd of to get rid of the skull effects was to turn off the x-box 🤔