Yeah, you'll have to fix the pictures in order for the MOC to get accepted.
That said - this is so much better than the first version. The new shoulders help a lot at making the MOC look more interesting and the torso is far better now, too.
The "lower" shoulders stick out a little much in my opinion, though.
As to the backstory - you should probably add the fact that Rerekei didn't like what the Brotherhood had become and - full of shame - didn't even fight back when the Matoran came for her.
Also the fact aside that no island south of Keetongu's island is part of the "known" Universe - I've been working on a map showing all the regions assigned to Makuta and there actually are no islands left. You'd have to settle for a region on the Northern continent or on the Southern continent.
Fix the pictures and the backstory and I'll accept Rerekei.