A = Affection (How affectionate are they? How do they show affection?)
Due to the circumstances of her life she is ready to both give and receive any form of affection. She’s very careful about finding out and sticking to your preferred love languages.
B = Best friend (What would they be like as a best friend? How would the friendship start?)
As usual with Fate someone has to be master and someone has to be a servant. As a friend she can be a bit of a tease but is nice overall.
C = Cuddles (Do they like to cuddle? How would they cuddle?)
She almost always falls asleep when cuddling. The feeling of warmth and security really helps her relax.
D = Domestic (Do they want to settle down? How are they at cooking and cleaning?)
Caster tries very hard to be a good housewife to varying degrees of success. Most of the time before cooking anything she has Shirou give her a lesson. She’s happy to clean as long as it doesn’t intrude on your time together. If it does she’s having the golems do it. One thing she does excel at is sewing, she’s great at fixing up your clothes and even making new ones.
E = Ending (If they had to break up with their partner, how would they do it?)
You will be betrayed and killed.
F = Fiance(e) (How do they feel about commitment? How quick would they want to get married?)
While she would be over the moon if you proposed it’s very hard to actually pull it off. If she sees you moving around suspiciously or trying to keep something from her her paranoia will get the better of her. This will most likely lead to you getting stabbed and bleeding while she monologues about how she saw through you and knew you were cheating. When you tell her about the ring she immediately does a 180° and starts apologising through tears while healing your wound and saying how happy she is.
G = Gentle (How gentle are they, both physically and emotionally?)
No matter what kind of person you are or what she’s doing she always has an extremely delicate touch.
H = Hugs (Do they like hugs? How often do they do it? What are their hugs like?)
Everytime you get back home she jumps you with a hug giddy to show you what she’s been working on in your absence.
I = I love you (How fast do they say the L-word?)
She would not hold back about gushing to anyone who will listen how much she loves you but only if you’re not present. When she attempts to say it directly to you she gets incredibly shy.
J = Jealousy (How jealous do they get? What do they do when they’re jealous?)
Easily gets jealous due to her paranoid nature.
K = Kisses (What are their kisses like? Where do they like to kiss you? Where do they like to be kissed?)
She would enjoy long romantic kisses.
L = Little ones (How are they around children?)
She is honestly amazing with children. Actual peak parent material.
M = Morning (How are mornings spent with them?)
She’d be very happy if you two had a routine together. Nothing special but things like brushing teeth next to each other, making breakfast together and that kind of stuff.
N = Night (How are nights spent with them?)
She likes going on walks with you at night. The empty streets allowing you to soak in each other's presence.
O = Open (When would they start revealing things about themselves? Do they say everything all at once or wait a while to reveal things slowly?)
A big part of the relationship would be helping her deal with the way her past has affected her so it would be a gradual process.
P = Patience (How easily angered are they?)
Mostly patient but there are certain things that tick her off really quickly.
Q = Quizzes (How much would they remember about you? Do they remember every little detail you mention in passing, or do they kind of forget everything?)
She would do her best to remember a lot of the things about you.
R = Remember (What is their favorite moment in your relationship?)
It would be the first time she got paranoid and thought you were doing something behind her back only to be proven wrong. It’s something that may seem stupid but it means a lot to her.
S = Security (How protective are they? How would they protect you? How would they like to be protected?)
She would put so many protective spells on you that you might actually end up bulletproof.
T = Try (How much effort would they put into dates, anniversaries, gifts, everyday tasks?)
She would always have elaborate plans she ropes anyone she can into.
U = Ugly (What would be some bad habits of theirs?)
If I haven’t made it obvious yet she has major paranoia/trust/attachment issues.
V = Vanity (How concerned are they with their looks?)
She is far more interested in putting you in cute outfits than dressing herself up. Combined with her sewing skills you’re in for quite something.
W = Whole (Would they feel incomplete without you?)
Losing the one person in her life that didn’t use or betray her would definitely lead her into going completely insane and lashing out.
X = Xtra (A random headcanon for them.)
At some point in the relationship when her insecurities get the best of her she would decide to use a love potion on you. However whatever she’d try seemingly wouldn’t work. She tried slipping it into your drink, putting it in food and even convincing you to drink it directly but nothing seemed to have an effect. She knew it should be working due to her proficiency in crafting and she even tested it on other people. She would eventually confront you about using some form of protection magic or being under the influence of someone else’s spell. This leads to you explaining that there’s no change because there’s nothing to change. She has never been more embarrassed in her life.
Y = Yuck (What are some things they wouldn’t like, either in general or in a partner?)
She would not enjoy you being secretive.
Z = Zzz (What is a sleep habits of theirs?)
She insists on always sleeping with you no matter how small the bed.