[quote=@SilverPaw]
You mentioned our characters memories with Regret are lost. Then, have they also absolutely zero recollection of their previous life initially?
[/quote]
This element is primarily a plot device added to give me leeway to introduce your characters to Regret over time, since granting them full knowledge of their former patron will make choosing her too easy and complicate my efforts to characterize her properly (because how do you convey an entire relationship with a friend in a few paragraphs?). But I also think they should retain some knowledge of their past lives before they met Regret so that their personalities can properly form. So given the specificity with which their memories were lost, I'll have to say Yddrog probably wiped them on purpose during their creation/summoning ceremony.

[quote=@SilverPaw]
Do they they regain their memories over time? Or does it vary case by case, maybe even depends on whether they try to remember or other factors?
[/quote]
My working plan for this is to roleplay out "character memories" between the Champions and Regret whenever they accomplish something significant. But I've rarely known RPs to pan out the way I intended, so this is subject to change. In short, it'll vary and may depend on various other factors. Off the top of my head, I can envision them recovering their memories through things like:
* Adjusting their bond with her
* Meeting people she associated with
* Doing things she'd appreciate

[quote=@SilverPaw]
When did Regret become involved with Aetherion, when she was still human or afterwards?
[/quote]
Several thousand years ago. She was an ordinary human colonist back then, a microbiologist paid for her contributions to terraforming endeavors. When a Rift opened and the Voidspawn started pouring out to conquer her world, she shifted gears to become a doctor and help the war effort, and eventually took on additional roles as the situation grew worse. Long story short, humanity lost that war and was driven to extinction. Regret was the last human standing on the entire planet. She bargained with her god to grant her power and immortality so she could avenge the fallen, challenging him whether the extinction of humanity and victory of evil was truly his will. She got her wish, and over the next thousand years proceeded to hunt down the Voidspawn one by one until she'd wiped the planet clean of them. The abilities she developed during that lonely war are the ones that'll be handed down to the players - Healing and Rot, Adrenaline Rush/Hysteria, and Offensive Reincarnation being the three key ones.

[quote=@SilverPaw]
Does she consider it 'her' kingdom/does she show it preference?
[/quote]
That was part of her second bargain with her god at the conclusion of her Lonely War. When she'd finally avenged humanity of its enemies, she challenged her god once again whether a barren, lifeless world without man was truly his will, and offered to restore new life to the world in exchange for undying life of her own. She got her wish, trading away her power in exchange for increased authority and keeping her immortality, and continues to nurture the world as its mother and guardian to this day. Aetherion in particular is a nation grown from her direct descendants, so it holds a special place in her heart.

[quote=@SilverPaw]
How influential is she as a demigoddess?
[/quote]
Uniquely so. As the only patron with a physical, mortal presence on this world, and one who grants immortality at that, her name is widely known here, though her level of influence depends on whether they have a good opinion of her. In Aetherion, her word might as well be law.

[quote=@SilverPaw]
I take it Yddrog is an unusual exception as a contractor in how much he can defy his patron (and creator)? Is that because Regret was too lenient in their contract, gave him too much power for 'free'? Or did he also manage to rebel because of his innate will?
[/quote]
Yeah, he's an unusual case. She was a fairly new Ascendant back when she created him, so she was inexperienced with the creation of magical contracts. Her contract with him did not include anything that bonded their minds together, so his will was almost entirely free of external influence. This proved to be her undoing. Naturally, she did not make the same mistake again when she contracted with her Champions.