Charm Believix is like Charmix, but this level is for those who started out as a Believix fairy. Like the group, Rosix club, they started with Believix because their relatives(the Winx) were Believix or above(It is unknown how Ella has started with Believix too because she is Diaspro's sister)
How to achieve it[]
Same thing when you achieve Charmix.