User blog comment:RoyallyBella/Official Season 7 discussion blog/@comment-5875378-20151003132723/@comment-26964215-20151003135700

Maybe Rainbow brought the Trix back to make things a little interesting. I mean, who thought we'd ever see their faces again? All of us knew that they were locked in the Legendarium in the Season 6 finale... and we thought this was forever. There's also a twist to how the Trix would have powerful Fairy Animals...right? But anyway, these are all my thoughts on why the Trix are back.