Well I certainly wouldn't mind developing Joseon and the Samhan a bit more or perhaps Nippon. Or really any of the Zhongguo biomes I've skimmed over so far.
Storm Unit
Ifani Brandt
Ifani is outwardly taciturn, prickly, sharp tongued, confident and assertive. She keeps all at arms reach save Albert, her childhood friend. She can be intimidating to all who threaten herself or Albert. She is intensely protective of him despite occasionally trying to toughen him up and Albert is equally protective of her in his own ways. She has become reliant on his support and perspective, Albert always looking out for her. These two were an island for the longest time, Ifani entirely oblivious to Andrea's infatuation and only seeing her as a rival swordswoman as Ifani has a deep distrust and criticism for nobility despite being noble herself (of the lowest rung). Underneath her tough facade, she is immensely kind, warm, caring, considerate, brutally honest and straightforward and hides considerable uncertainty and softness. She is a comfort and stalwart ally to those she cares for and there is nothing she wouldn't do for her chosen family. She is super critical of herself, especially in regards to her "wierdness" (autism), feeling the need to prove herself more than any other, both to herself and the society which has criticized her for all but her ability to fight. And she has begun letting more people in, however cautiously, starting with Tia
Brynjar
While his sister is quiet and reserved, Brynjar is extremely outgoing, boisterous and straightforward. He is also excessively protective of Inge especially after she lost her sight. Brynjar quickly comes to admire and become infatuated with Ifani, admiring her strength, diligence and honest nature and finding her extremely beautiful. He has an adventurous soul but can be very serious about his sister and her past. They fled their ostman village due to certain events involving Inge and how she lost her sight, both hopeful about a new start. Brynjar insists Inge keep a number of secrets about her past and abilities. Sometimes he forgets about his own happiness. Brynjar has and will always feel guilty and at fault for what happened to Inge. This is part of why he works so hard to protect and watch out for her now, hypervigilant. This is especially true because Inge once gave up a chance for a pampered life in the branches of Yggdrasil to remain with him after their mother died. This choice, forsaking a life surrounded by others like her who understood her unique abilities, has only further left Brynjar ingratiated, regretful and guilty in his failure to protect her.
Orin
Despite his charm and charisma, Orin is a very manipulative and ambitious nobleman. He judges those around him harshly behind a smile and flirts incessantly with Tia. Despite his beliefs and ego, he can be extremely charming and isn't afraid to use his good looks to his advantage. He is also far more intelligent than many assume. He is in fact Leon's cousin but his parents were caught in a scandal which lowered his father's station. Orin is extremely bitter towards his father for his failures, this hatred furthered by his father's alcoholism. He believes he is meant for greatness and intends to save his family through service and marriage. Both Andrea and Leon recognize and admire his ambition. He also has a reputation as a player and status chaser, but he carries some horrid, grave secret which is is greatest shame. Orin is skilled in assessing the mental states of those around him and in manipulating certain emotions to his advantage, mastering the art of provoking others to give him something to work with
Bolorbataar
Bolor is a man deeply entrenched in the customs and traditions of his people most of his life. He loves his kin deeply and highly values community and comradery. He is jarred by the sudden shift of his life but was eager for recruitment for the purpose of finding Gan, who originally taught him his passion, hunting, who had never returned from service. He also has come to enjoy travelling and seeing the world despite this unfamiliarity. He struggles to learn Accian and his refuses to conform to Accian norms, sorely missing his old lifestyle. But one might not guess this as he is amiable and boisterous with a ready smile. His language barrier still makes it hard to form bonds, thankful that Longwei has taken the time to learn his language. However, he is persistently kind, respectful and generous to all those around him, valuing hospitality, brotherhood and mutual respect. Simultaneously, he keeps an invisible barrier between himself and those of outside cultures, viewing the world through the lense of his own culture (ethnocentrism). Quick to dismiss outside beliefs as silly or unimportant, finding and bringing Gan home his only goal, originally. Despite this barrier, he comes to care for his unit-mates as if they were family, something he had never expected, challenging his views. He find beauty eventually in the places they travel and similarities between the heart of his own culture and these new practices, trying to do so without losing his own cultural identity at his core.
Albert
Albert is a young scholar, musician and tactician. He and Ifani have been friends since childhood, sticking together through their hardships, and both are very protective of each other in their own ways. They tend to be polar opposites but respect the other's skills. Ifani does become frustrated with his lack of confidence, despite his various talents. He worries too much about her and how she is adapting. While a terrible warrior, Albert became a certified scholar at a record age thanks to his magic and comprehensive skills. Despite this, he is rather insecure. He can be surprisingly cynical and it takes time for him to trust people. While he can insecure, he is astonishingly firm when it comes to defending his friends. Albert is a devoted academic, seeking truth and enjoying comparing, consolidating and theorizing. Albert is naturally kind, gentle, and hopes to add some good to the world with an endlessly big heart. Simultaneously, he is cynical, mistrustful, shrewd, firm and unrelenting. It is partially this kindness that makes him a terrible warrior, extending out to anyone "different" or who is treated as an "outsider". Albert was bullied constantly growing up in the capital as a commoner, brushing shoulders with royalty and nobility on unequal ground. This is part of why he is timid and reserved by nature—he was expected to be. This left him with a severe distaste for bullying, maltreatment of outsiders or oddballs and general haughtiness. This has unfortunately made him very mistrustful and reactive to manipulation, toxic behavior or general deception. It is only in the defense of his friends or any outsiders that his stalwart, uncompromising and cut throat side emerges. Despite his reservations, Albert strives towards a brighter future. He is hopeful Accia is redeemable, clinging to the better qualities he sees in rejects and outcasts. He tenuously believes Aldric is capable of being a better king than his father, if he can learn to be his own man. These dreams are uncertain and brittle but he clings to them nonetheless, doing all he can so he and his friends can stride forward.
Arabella
Arabella has a strong and confident personality. She can be very contrary to social norms and she likes to stir up chaos. She can still be incredibly inclusive, affectionate and nurturing to those she's chosen. She is a mother hen, both protective and encouraging growth in others but she isn't afraid to criticize them harshly as well. She values loyalty, honesty and spirit. Unfortunately, she can also be draining, demanding and has a poor sense of boundaries. Arabella was born into a simple farming village. Her mother was born with the ability to summon rain but Arabella summons storms instead and has been discouraged from using her ability at full strength most of her life, especially summoning lightning. She is excited she no longer needs to stifle herself. Arabella is a lesbian and polyamorous, making no effort to hide or stifle her preferences. She can be somewhat pushy in this regard but enjoys giving advice and educating her friends on positive sexual health. Arabella is obsessed with romance and battle. She hopes to prove her strength and gain opportunities so she can become more than a simple farmer.
Longwei
Longwei works hard to prove himself in a world which doesn't recognize him. Despite Longwei's confidence in his gender identity, a lifetime of having to prove himself has left him angry, bitter and understandably exhausted. His small frame and feminine face are a source of insecurity and frustration for him. He can have explosive anger, bursting out suddenly and viciously. Until arriving at the valley, it was just he and Bolorbataar. Bolor is the first human to recognize and accept Longwei as male and they become fast friends, surprising most around them as they seem total opposites. Bolor has become accustomed to disarming or redirected Longwei's anger to keep him from trouble. Longwei's greatest pride was being chosen by Wulong, a bond azure dragons reserve only for men which was the first outside recognition of his identity even if his clan was furious and refused to acknoledge them. Longwei was Wulong's caretaker before this, the two of them behaving like siblings. Outside of this anger, he is cool and composed, listening quietly and observing those around him before offering up sharp words, quite enjoying crafting creative insults and having a skill for learning and wielding new languages. He also has an inner serenity, a gentleness only few are able to appreciate. Longwei is considerate and defensive of outsiders like himself and Bolor. He doesn't tolerate bigotry or bullying and is quick to defend anyone and everyone. Despite their practical ousting of him, he values his clan and strives to prove to them who he is. He loves his culture as well, revering the Si Xiang. He is quick to show that immense respect to Wu Zetian and Shi Yang. Longwei shares the Zhou's dream of redeeming themselves but his relationship with his kin is otherwise strained or even malicious, believing if he can redeem the Zhou in the eyes of the Si Xiang, his clan will have to accept him.
Wulong
Wulong is an Azure Dragon born and raised within the lake beneath royal palace of Zhongguo. Wulong is fairly young, only recently reaching full maturity. Her own parents had died during the attack so she was primarily cared for by the women of the clan. Because of this, Longwei interacted with her often in their childhood. Despite these creatures usually being standoffish and mysterious, Wulong is extremely affectionate and playful with Longwei. She cares for him deeply and their relationship is like that of siblings. She is, of course, still a prideful creature and tends to be standoffish towards everyone except Longwei. Wulong doesn't particularly care for violence but will still protect Longwei fiercely. This is one of the primary reasons Wulong and Longwei have taken up a support role rather than becoming cavalry. Wulong enjoys using her abilities to flit about the battlefield and aid allies instead. Wulong is registered within the stables but will often find a nearby body of water to occupy when it isn't appropriate for her to be near Longwei. She misses being waited on by the clan. Longwei tries to help her with this when he is able.
Inge
Inge is reserved, contemplative and quiet. She is very intuitive and pays close attention to others. It is in Inge's nature to help people, seeing the best in others even while witnessing their worst, and she struggles to stop herself from butting in even with personal problems. However, after a lifetime of backlash, she has become more hesitant. She's begun to expect people to rebuke her or worse. A lot of her fear stems from a traumatic event that left her blind. Brynjar has become particularly protective and vigilant after this event. She still laments losing her sight and struggles to navigate as she has not been blind for very long. Despite this, she still wants to use her abilities to help people and is trying to continue to see the beauty in the world despite so many foul experiences. She is most cynical of her own future and value. Brynjar has made her promise not to use her ability to interfere with people and to hide the full extent of what she can do. She tries to keep her promise not for herself, but for her brother feeling her own guilt for forcing them to have to leave their home. In childhood, when Inge was discovered to possess Ranalis' blessing, the pampered and lofty life of an alfar was set before her. Inge rejected this opportunity to remain with her brother. Without their training, Inge had a lot of trouble tuning out or controlling her sensitivities. She was quick to become overwhelmed and this made her prone to bullying, becoming quite shy and reserved. Brynjar made a habit of coming to her rescue and became very protective of her. Despite their difficult past, the two of them are looking forward to seeing the world and having a fresh start.
Sorry I know some of those got long. Its hard to leave too much out of their character description for me!