Character Details
Whenever a guest walks into the Cat's Tail, they will immediately glance in the direction of the bar.
Behind it often stands a girl with mildly-twitching cat ears, cocktail shaker in hand, and an unhappy look on her face.
This is the mixologist Diona, ascendant star of Mondstadt's wine industry, and the greatest challenger to its traditional powerhouses.
However, she does not make these wonderful cocktails on purpose — indeed, quite the opposite.
Her mixing methods can seem a little "inscrutable" to an outsider. To herself, Diona tries nothing less than her hardest to ruin that hateful grog.
But no matter the drink, it will turn out to be an unimaginably sumptuous brew so long as it passes through her hands.
This is a "blessing" she has received, though that blessing is a huge headache for her.
For this mixologist proclaims herself to be the "Wine Industry Slayer," and her final objective is the utter destruction of Mondstadt's entire wine industry.
Character Story 1
Coming to the Cat's Tail to serve as its bartender was really a prank on Diona's part, the first step in her master plan.
When patrons came in, they would "enjoy" her look of disgust as they got ready for the "Diona Special"...
"Hmph. Here, drink this Sea-Salt Lizard, and kiss your life as an alcoholic goodbye..."
So she would say, thus ruining these boozehounds' appetites.
And yet...
"*glug*... *glug*... Wow, I have never had such a wonderful drink! Can I get a refill, miss?"
"...You want a refill!?"
To this day, Diona has struggled with her unbroken record of mixing fine drinks. Unable to accept defeat, she has yet to give up on her dream of producing something truly disgusting.
However, the results are always the same, and the Cat's Tail remains a popular watering hole, with its pleased patrons singing praises unending of her skill.
All poor Diona can do is puff up her cheeks, tears forming in her eyes as she grumbles:
"Just you all wait!"
Character Story 2
Diona's father, Draff, is the best hunter in Springvale.
With a resolute face, honed hunting techniques, and calm judgment calls, he fully deserves to be the leader of the huntsmen of Springvale, and is an example to them all.
In Diona's young mind, her father was her shining, perfect idol, the person she wanted to be.
And that was also why she cried her heart out the day the pedestal she had put her father upon abruptly shattered.
"When he's drunk, he's like a wild boar rolling about in the mud!" So she said, her eyes ringed red.
But Diona was not ready to blame this on her father's terrible drinking habits, for how could such a great father have such faults?
"It's the wine's fault! It bewitches people and makes them stupid!"
This is the source of Diona's hatred for alcohol, and the beginning of Cat's Tail's turn in fortunes.
That said, Margaret, the owner of Cat's Tail, had never expected any of this to happen at all. Rather, she had a much simpler reason for hiring Diona.
"What choice did I have? She's just too cute."
Character Story 3
Many patrons believed that Diona's feline ears and tail were part of her uniform as a bartender.
This persisted until one day, when one particularly plastered fellow tugged her tail out of curiosity... only to find it unexpectedly warm and soft.
That day, Diona turned the tavern upside-down.
These feline features are the hallmarks of those with Kätzlein blood in their veins, and it is an exceedingly rare sight in Mondstadt.
Other than such aesthetic similarities, Diona and her father Draff also owe their prowess on the hunt to this ancient bloodline.
Infiltration, archery, climbing, and dodging... Diona required no teacher for such skills.
"Ah, yes, and she also has a pair of eyes that can see well in the dark."
"As for weaknesses... She bites when piqued, so please be careful."
Thus did Dr. Edith write of Diona in her notes for "Studies Into Bloodlines Strange and Unfamiliar."
Character Story 4
Diona's appearance did indeed have an impact on Mondstadt's alcohol industry.
The Dawn Winery's long-held monopoly was broken overnight by this unexpected ambush from Cat's Tail, and the man put in charge of the winery's business, Elzer, found this unacceptable.
A calculating veteran of many industrial battles, Elzer considered poaching this key figure, never realizing that Diona considered the Dawn Winery a sort of "final boss" to be defeated in her quest.
"This marvelous and bold method of preparation must be the secret of these flavors, yes?"
Diona simply looked at the white-haired man who had just sat down in front of the bar, rank displeasure in her eyes.
"Ah. Simply exquisite. I can just feel your incomparable passion and love for wine."
Diona's hand started to tremble as it held on to her cocktail shaker, and detecting the change at once with his sharp gaze, Elzer understood immediately.
"If a brilliant bartender as yourself were to grace the Dawn Winery with your cooperation, we shall be able to bring Monsdtadt's alcohol industry to heretofore unseen heights!"
...When Diluc questioned Elzer as to the story behind his bandaged hand later, he was uncharacteristically hesitant to say anything.
"I... I was bitten by a cat."
Character Story 5
There is a legend about a "spring fairy" that circulates in Diona's hometown.
The fairy once saved a mother and son who had despaired beside a well, filling the barren hole with rushing waters that pooled and formed a spring. The child, deathly ill, was miraculously healed by those spring waters.
Many people came to catch a glimpse of these blessed waters, and built a settlement around it, and left it not thereafter. Over time, this gave rise to the small town known as Springvale.
Nowadays, few are left who believe that this is any more than a mere legend, and some even dismiss it as myth-making for tourism's sake.
Only little Diona believed in the existence of the spring fairy, and on nights when her father was in a deep stuporous sleep, she would speak to the moon reflected in the spring water's surface.
These were her earnest feelings, innocent and wonderful — feelings worth answering.
That was what the spring fairy believed.
So, Diona would make a curious friend, a companion whom she could bare her feelings to and sometimes assuage her loneliness.
On the night of Diona's seventh birthday, as the moonlight reflected off the spring and upon her face, she heard the soft voice of the spring fairy.
"I will bless you, daughter of hunters, for your days ahead, and as a farewell. May your cup always run over with the sweet wine of celebration. May it always be refreshing as springs of ever-melting snow."
From that day on, the spring fairy would never appear before Diona again, and she left those memories behind, consigning them to her childhood dreams.
Till today, she has yet to realize that her troublesome constitution has anything at all to do with that dream.
Cold Cocktail Shaker
Diona's father Draff is also interested in mixing the occasional drink.
Diona's tail would wag from side to side of its own accord as she watched her father rocking the shaker back at forth at night.
But young Diona also found that her father would wind up particularly drunk on such nights, becoming dead to the world before he could even finish her bed-time story.
Thus, when Draff went out to hunt one day, she hid the shaker, squirreling it away in the deepest place under her bed.
Unexpectedly, her father didn't bother looking for the lost shaker at all. He simply brought a new one back the very next day.
When Diona went to Cat's Tail to try out for the role of bartender, Margaret noticed how the cocktail shaker Diona had with her looked wholly unsuited for her style.
Ever skilled with handicraft, Margaret would give Diona a cocktail shaker equipped with a lovely cat's tail as an induction gift.
"Now, this suits you far better," Margaret said with a satisfied nod.
Vision
Diona's antipathy towards alcohol is not "hate" per se. Instead, it can be considered a form of "avarice."
She wishes for her father to always be the man that she admires, and she treasures every moment that she spends with her family, unwilling to "share" her happiness with the wine.
There was once a storm that lasted for three days, and for those three days, her father, who had been out hunting, did not return.
The awful weather prevented the search parties sent by the Knights of Favonius from making much headway, and soon the dread of "loss" began to hang over Diona like a shroud.
If she could not even stand to "share," how could she bear having something utterly "stolen" from her?
She burst out the door and into the tempest, and the waters that stood in her path were frozen by some power she did not recognize.
Using her superlative tracking skills, she found her father under a broken gorge.
With the help of the other hunters, she returned home with her father, and only once she realized that he would be fine did she finally smile again.
"Do you... want me to mix you a drink? It'll numb the pain a little..."
That was probably the first time she ever mixed a drink in a normal fashion.
"Ooh, it's so refreshing. It's wonderful! Hahaha—Ouch..."
Getting to drink a cocktail that his daughter had made was probably a better anesthetic by far than the alcohol itself.
Still, Diona gaining power over Cryo did not help reconcile her to wine at all.