Main Characters

Summer

Summer Belladonna-Xiao Long

The daughter of Yang and Blake and the twin sister to Kali/Cinder.

Berserk Button: She has several, with the most notable being Atlas as a whole and Marrow in particular, often restraining herself from flying into bitter anger at the thought of them.
Sticky Fingers: She has a distinct habit of pickpocketing. It was apparently a habit she gained from her mentor, the future version of Emerald.
Strong Family Resemblance: She looks a lot like Yang, save for her nose and cat ears.

Future Blake

The future version of Blake Belladonna and the mother of Summer and Kali/Cinder.

Happily Married: She's shown to have a loving marriage with her wife, Yang, as seen when they reunite during the events of the Atlas arc.
No Sympathy: In contrast to canon and her younger self, she shows nothing but contempt for Adam and kills him without hesitation after their fight.
Pragmatic Hero: The years of constant fighting and death have made her far more willing to take questionable actions than her past self would be comfortable with.

Cinder

The woman who brought about the Fall of Beacon, who is in actuality the time-displaced daughter of alternate future versions of Blake and Yang.

Antagonistic Offspring: She's a villainess and fighting against her own parents, neither of whom are happy about the situation.
Believing Their Own Lies: She's completely deluded herself into believing that every action she's taken is for the sake of her family despite how much pain she causes them to suffer.
Beware the Nice Ones: Back when she was still Kali, she tracked down and killed Ursala, the mastermind behind the Fall of Beacon in the previous timeline, showing that even as the sweet young girl who cared for her family more than anything, she still had a ruthless side that would become more apparent as Cinder.
Hypocrite: For all her claims that everything she does is to protect her family, she has no problem hurting or maiming them to force them to comply with her worldview. Additionally, despite having a hatred for abusers like Frost, who was abusive towards Summer, she's just as, if not more, abusive towards Emerald. Her constant double standards are one of the major reasons why Emerald chooses to defect from her side.
Used to Be a Sweet Kid: It's frequently commented that she was once just a soft, sweet child who wouldn't hurt a fly. That same child and the psychotic sociopath she grew up into have very little in common.
Walking Spoiler: Really, it's impossible to talk about this version of Cinder without bringing up that she's actually a time-displaced Kali Belladonna-Xiao Long thanks to it being a First-Episode Twist.