I'll start with
Nadrah Drorixerk.
Past Life
1) Who was the darklord before the mists took them? Nadrah was a slave who turned into a freedom fighter who turned into a terrorist and a war criminal.
2) Who were the darklord's family? Nadrah was named after her mother, who died in a mining accident while the girl was still in the egg. She was raised by her father, which many of her kind would say explains a lot: In dragonborn society, usually sons are raised by the father and daughters by the mother, and it's believed that a child not mentored properly would turn into a feral savage; But such claims are an insult to Nadrah's father, Rhesh, a kind man and a good parent who did his best to give the girl hope in a hopeless world. Nadrah's grandparents died when she was very small and she has no memory of them.
3) How was the darklord's family oppressed, oppressive or both? (Note: Do they have to be either? Not every conflict has to be about oppression... Even though my current ones are...) They were slaves to the red dragon Mag'ilorix, working in his mines from infanthood to death simply to add to his hoard. Many of the clan died prematurely due to collapses, lung diseases or extreme exhaustion, and those reluctant or too weak to work were often eaten by the dragon.
4) What was the darklord's childhood like? Nadrah worked in the mines since she could walk. Her being a child simply meant she could enter narrower spaces. There was no time for leisure or games during the day, but at night the clan would gather around the fire pit and sing together, and Nadrah's voice was always the loudest.
5) Whom did the darklord care about? Everyone in the Drorixerk clan. She learned very early how hard the clan's adults were working just so she and the other kids can survive, and soon took it on herself to shoulder their burden.
6) Who cared about the darklord? Her father Rhesh; Aunt Nira, the local leader of the rebellion; Clan Master Mathun, a man who deeply cared for his clan but strictly obeyed Mag'ilorix, believing resistance would only make things worse.
7) Who hurt the darklord? Mag'ilorix, obviously; Clan Master Mathun, who turned down the rebels.

Whose respect or love did the darklord crave? Aunt Nira, who indoctorinated her into the resistance movement. Nira was determined to bring freedom to her people, but only by honorable means, which doesn't go hand-in-hand with gorilla warfare. When Nira and her inner circle were turned down to the dragons and executed, Nadrah killed Mathun the traitor, took over both the clan and the resistance, and vowed to end the dragons' reign
by any means necessary.
9) What did the darklord value? Freedom. Justice. Her Family. Oaths being kept.
Wicked Personality
10) Ideal? Honor. What's the use of promises if you don't intend to keep them?
11) Bond? I vowed to overthrow my opressors, and it will
not be said that Nadrah Drorixerk is an oathbreaker.
12) Flaw? I refuse to change my mind, even if I'm clearly and disastrously wrong.
Developing A Darklord
13) What was the first depraved act the darklord chose to commit, and how did their ideal encourage them down this path? Killing Mathun was already kinda grey, but understandable. Her first 100% evil act was slaying Mag'ilorix' youngest son, Lokhar, who was barely older than a hatchling and as loath of his father's cruelity as the rebels.
14) Was the darklord rewarded or celebrated for their evil? Did that reaction encourage greater crimes? Was that reward earned or justified? Nadrah taxidermified (is that how you say it? English isn't my native language) Lokhar's head and presented it, impaled on a spear, at the center of the clan's new warcamp, 'as a proof that dragons can be killed'. The murder resulted in a prize on
her head, but earned her the admiration of the resistance and any clan aspiring to join it.
15) Did the darklord repeat or escalate their wickedness to obtain something they selfishly desired? It was never selfish, only in the name of liberation. Every broken egg, every decapitated wyrmling, not to mention the hundreds of
other slaves who were killed as collatoral damage, can comfort themselves that at least they died for a higher purpose.
16) Did the future darklord realise they were losing any hope of redemption, yet choose to commit other heinous acts in keeping with their flaw? Nadrah knew she was cruel, but convinced herself cruelity was the only option: Dragons only understand power, they're no partner for peace; They were too mighty and cunning to be defeated in a fair fight; and surrender was too shameful to consider. She cared about honour as much as any other dragonborn, but to her, honour meant one thing alone: To never give up her goal.
17) What act was so atrocious that the future darklord's friends and family reject them? Did the darklord think this was warranted or an unreasonable judgment? How did they react? After twenty years of war, Nadrah hatched a plan to destroy Mag'ilorix. She sent on the mission three kids, orphans adopted by the resistance: A girl with a tail, a genasi boy who knew the names of every herb and flower in the realm, and a bookish human sorcerer with a peculiar scar on his chin. None of them was over level 2, but Nadrah made them all drink an elixir that will give them the power to end the dragon's life. Nadrah's own daughter, Delphi, insisted she should go in their place or at least accompany them: She was older and better-trained, and the kids were more terrified than they showed. Nadrah refused to send her. Delphi asked why.
Nadrah avoided the question at first, but when the youth pressed, she admitted the kids were never meant to survive: the elixir gave them no special powers; it would simply make them release an extremely toxic gas if they're to be burned or digested, so the wyrm may die with them. Enraged, Delphi told her mother that she's become what she swore to destroy, and that she~herself is going to warn them. Nadrah sighed, thinking the girl is too young to understand the sacrifices freedom demands, and had Delphi locked in a cage so that she won't interfere. The youth escaped after two days, but by that point the unwitting martyrs were already on their way. She tried to follow them, but was too late.
18) When and how did these acts attract the notice of the dark powers? Nadrah was in the warcamp, planning the resistance's next operation and worrying for Delphi's fate when, unknown to her, the mission was completed. The mists could claim Mag'ilorix, of course ~ he was more than worthy; But then they thought: Who's the worst war~criminal, the one who kills children, or the one who sends children to die?
19) How did the dark powers use these acts to create the perfect prison domain for the darklord? Era'i emerged from the mists as a lush green valley, perfect for starting a new, free dragonborn settlement. However, Nadrah's ideals would not allow her to do so: She would not lay down her sword while her brethern in Abeir still toil under the dragons, while her daughter is missing (there are enough domains where the darklord's rebellious progeny is still part of the picture, dead or alive. Delphi is still alive in her homeworld and I hope she'll have a good life and never catch a glimpse of the demiplanes of dread.), while she's unsure whether or not her revenge succeeded.
This devotion could be dubbed recommendable, even heroic ~ but as always with Nadrah, her good intentions take her on the highway to hell. While she tries to find a way back to Abeir, her people are content with building a new, peaceful life in the domain. To keep them on the task so she may return with an army rather than a handful of loyalists, she must constantly remind them the horrors they fled from, using magic and gunpowder to imitate dragon attacks. Nadrah is now the sole cause of misery for the people she'd sworn to save, and deep down she knows this.
Monstrous Transformations: Since Nadrah was claimed by the mists, she resembles a dragon even more than the rest of her species. She's 3 meters tall, winged, and has an unsusually powerful breath weapon. This makes her a fearsome combatant, but she's always ashamed of using 'the opressors' weapon'. Yeah, the subtext kinda got over her head.