A certain someone has been pining for a Master for Saber...

[list][*][u]Name[/u]: Laetitia Arconiand
[*][u]Age[/u]: 18
[*][u]Appearance[/u]: [url=https://i.imgur.com/anG1iR0.png]She's, oddly enough, 188cm tall.[/url]
[*][u]Personality[/u]: A girl who takes amusement in teasing and annoying others, able to keep a level head when that inevitably blows up in her face or if a situation gets stressful. Despite Laetititia's attitude seeming to be rather unpleasant at first glance, she's remarkably good at never taking it too far--the point is to get a rise out of people, not distress them. On the occasions she does push it too far, she's quick to try and make amends--an altruistic attitude she ultimately applies to everything. Even if greed does have a massive influence in certain situations...
[*][u]Abilities[/u]: Laetitia takes odd pride in a certain claim: that she has but a single magic circuit. Not a vast number, nor a reasonable number of high-quality circuits. [i]One.[/i] Yet, so far as her family has been concerned, this is ideal: the embodiment of quality over quantity. Despite being but a single circuit, she's able to sustain a top-tier Servant without the degradation of their abilities and keep up with a certain Average One at least on raw output.
Then as a magus... well, it starts to get weird. Her affinity is for True Ether. Another thing her family prides itself on despite being somewhat of a defect in this day and age--no True Ether remains in the world, nor can it be actualised, and thus achieving magecraft more advanced than Reinforcement is beyond them no matter their power. Were she to achieve their current goal, this might be reversed into the strongest of affinities, but...
What the Arconiand family magecraft can [i]currently[/i] do is essentially meta-magecraft. True Ether is a more powerful substance than Ether, and thus an affinity for True Ether leads to a branch of magecraft that excels at something thought impossible nowadays: modifying or negating magecraft with only magical energy. Taking the target of a spell and reversing it, breaking an enchantment, amplifying the powers of some skilled but weak or exhausted magus... in everything but the [i]casting[/i] of spells, they are remarkably adept.
[*][u]History[/u]: The Arconiand lineage harks back to the unknown past and claims to be descended from dragons--a fact they attribute their absurdly powerful but limited circuits and unusual affinity. Unfortunately, this has [i]also[/i] lead to a family tree that seems to actively make itself as narrow and impossible to map as humanly achievable in the pursuit of maximising this draconic purity.
Most immediately, however, Laetitia's parents were both in the odd situation of being enforcers--with this sort of magecraft, the contributions one can make to the Association are rather limited; either assisting other work or hunting down mages who think themselves safe so long as they have enough protections. Other portions of the family focus more on the long-term goal of finding a way to draw on the reverse side of the world where it might be possible to access True Ether, and from there... the Root.
Fusang and its abundance of Servants seemed like yet another opportunity to possibly achieve this--or at least study Casters from the Age of Gods for clues--and as such she has several cousins present as well, and her parents took the opportunity to stop risking their lives daily and live here. 
Most notably, the family as a whole doesn't shun technology. It would be rather inconvenient from their perspective to rely on solutions born from magecraft, when such things are even [i]more[/i] easily broken and they lack the ability to replace them. Rather fittingly, they hoard wealth like nobody's business.
It could be said that Laetitia is the most powerful of the current generation, but she's also far from the main line and currently disinterested in arguing that the crest should transfer branch. No matter how powerful the circuits entrusted to it are. 
[*][u]Other[/u]: From a rich family, but definitely dependent on them.[/list]