Actually, I'll have to agree with Nexx on Sheryl. She's an interesting take on the "defrosting ice queen" (or more classic tsundere as compared to the more modern "slap slap kiss" type) where her she's "thawed" pretty early on showing a pretty complex and well rounded character. That, and the way she handled adversity after episode 14, where while she was down in the dumps, it was still mostly through her own effort and determination (albeit with support of friends) that she got back up on her feet - that moment in "Diamond Crevasse" where she stands up and sings in the shelter in a time of despair was a very powerful moment as well a more grounded take on the power of song (to give hope in times of despair).