I've been browsing the Internet lately, and an article on Wikipedia sparked my interest. I know what you're all thinking, but before you jump down my throat about not trusting Wikipedia, listen up.
This small paragraph on Roxy's page caught my attention:
It is unclear how [Roxy] earned her Believix without someone believing in her being a fairy. However, it can be argued that it was similar to how Bloom earned their Enchantix; just like Bloom was angry at Valtor for everything that he did to her, Roxy was angry at Gantlos for hurting Artù, so it's quite possible that she 'willed' her Believix like Bloom with her Enchantix, initially.
I originally planned on writing a post about Roxy's powers, but I thought might be a little more interesting if I pointed out the similarities between Roxy and Bloom. They both:
-Didn't know they were a fairy (at the begining)
-Have a mysterious family
-Have prophetic dreams
-Have a close animal companion (Artu, Kiko)
-Earned their fairy form differently than normal
-Reside in Gardenia
-Are the main target of enemies
Is this the reason why Roxy has taken Bloom's place as star in the forth season? Because she's basically identical to Bloom?