This was requested by smolwhiteferret from Wattpad. We're gonna change Zhongli's lore a little, and say that he is the older twin. So you're basically Zhongli's younger twin sister. No that does not mean you look like him, do remember that most non-human beings can change their physical form.
You use a claymore. I usually leave the weapon up to the reader when you're not the Energiro Archon, but I wanna switch it up a little.
"You, met someone?" Zhongli asked, raising an eyebrow to his younger twin sister, as she sat across from him. The tone of his voice was not helping (Y/n)'s confidence with telling her brother about her taking an interest in someone. Especially if it is a human. "And... who is this?"
"Oh... someone you've met..." The younger twin laughed nervously. If she were to tell her brother who it was... he might kill him... and she did not feel like burying her partner.
"(Y/n)," Zhongli said, using his sister's human name. Ever since he had retired from being the Geo Archon, which earned him a slap and a month of the cold shoulder, the two had dropped their Archon names. Morax has used his younger sister's name as the name of the currency throughout Teyvat, Mora, to pay tribute to his little sister being his right hand during the Archon War. That, and she threatened him with a thousand years of the cold shoulder if he didn't. "You remember the last time you had fallen in love with a human, correct? They had grown old and passed away, and you said you'd never fall in love with a mortal ever again."
"Pft, I'm over him." (Y/n) said, waving her hand like she was swatting a fly away, a nervous laugh escaping her mouth.
"You still go to his grave and cry." Zhongli pointed out.
(Y/n) had a nervous smile on her face, and coughed. "I-I mean... yes... but that doesn't mean I'm not over him. It's just sad to remember the day he passed away, and who wouldn't cry?"
"Someone who should have moved on over 200 years ago." Zhongli said.
"You're such a mean brother..." (Y/n) mumbled, before she changed the topic from her past lover. "Anyways, I have a plan."
"You are not turning them immortal or asking Annika to turn them immortal." Zhongli said, sipping his tea. He knows how his sister's mind works, no matter how hard she tries to throw him off.
"Ugh!" (Y/n) hit her head on the table, her plans foiled by her brother. "Oh come on Zhongli. He said he would become immortal for me."
"And so did you last lover, but he changed his mind, and look where it got him, and you.." Zhongli pointed out.
"Stop being right...." (Y/n) whined, wanting her brother to stop using logic for once.
"So, when am I going to meet this mortal?" Zhongli asked, looking at his sister curiously.
"Hopefully never..." (Y/n) thought to herself, but laughed on the outside nervously. "W-well... I had asked him to join us for lunch... and he said he would... so he should be on his way right about now."
"Hello Mr. Zhongli," A familiar voice made Zhongli freeze, and slowly turn his head to the side, seeing a familiar man with dead ocean blue eyes. "And hello to you, (Y/n)."
Zhongli slowly looked from Childe over to his little sister, who was sweating profusely, face flushed red from embarrassment, and ready to join Osial under the ocean.
"WHAT!?"
"You chose him!?" Zhongli asked, pacing back and forth in front of his sister, who was sitting on her knees in front of him, letting him express his thoughts and emotions. "Him of all people! (Y/n)! He is a Harbinger! And do I have to remind you that he had almost sunk our nation?!"
"Wait he what?" (Y/n) asked.
Zhongli forgot to tell his sister about that, since she wasn't in Liyue during that whole fiasco. She was in Sumeru, wanting to read the books the library had, hoping to bring some back to Liyue so she could share them with her brother. "Ok, you didn't know about it because I didn't think it was worth telling you, but basically he had woken Osial up to try to bring me out of hiding so he could take my Gnosis for the Cryo Archon."
It took (Y/n) about 5 seconds to process what her brother had said, before she sighed. "Oh brother... and you didn't think it was necessary to contact me so I could take your place... why?"
"You are my little sister, the burdens of life should not be on your shoulders, I am the older brother, it is my responsibility for you to stay safe and out of harm's way." Zhongli said. He had always felt like he is the one who needs to take the burden of life, rather than his sister, even though she is only 4 minutes younger than him. "Besides, I am not letting you face Osial or get involved with the conditions that I had agreed upon."
"You need to trust me more," (Y/n) sighed. For years, she had told her brother that she will take on some of the responsibilities because they are siblings, and siblings share responsibilities. Well, some siblings, the twins have witnessed siblings who will sell each other for a single apple. "I'm only 4 minutes younger than you, not 4,000 years. I have been through everything with you the moment we saw each other."
"I trust you with other things, but choosing your partner is not something I trust considering you have taken likings to mortals, who will not live as long as we do, obviously," Zhongli sighed, sitting down in a seat, his face buried into one of his hands as he was thinking about what his next move should be regarding (Y/n) and Childe's relationship. "You had loved a mortal and spent hundreds of years mourning him, and now you've chosen someone who would cause harm to me and our nation, along with being a mortal."
"Look, I didn't know about what he was doing to you and our home," (Y/n) said, pointing out a fact since Zhongli had forgotten to say anything. "But wouldn't it be best if I learned my lessons about relationships through my experiences instead of what you predict will happen? I will never learn unless I experience it."
Zhongli couldn't argue with his little sister's logic. She was right, it would be better for her to learn her lesson about relationships if she were to experience it rather than her brother trying to predict what happens or trying to meddle in her relationships with the mortals. But that doesn't mean he won't try and interfere sometimes. "Fine, I guess you are right. But the moment I feel like he is pushing your boundary I am killing him."
"Morax," It was rare for (Y/n) to use his Archon name, but sometimes it was the only name he would listen to. "If he were to buy me a flower you would try and kill him because you'd think he is trying to kill me with pollen, from one flower."
Zhongli groaned in agony.
"So, I am guessing your brother did not approve?" Childe asked as he sat with the younger twin as they sat together at the harbor. They thought it would be best to do something small for their first date together, which was just sitting and talking in a public setting, and somewhere where Zhongli could easily see them.
"He was ready to crush you with a rock," (Y/n) laughed nervously. "He is so protective of me. He told me about what you tried to do to my home."
"Oh..." Childe was hoping that wouldn't be brought up. "That... yeah..."
"I told him it was best if I learned my lesson with this relationship with you if I were to experience this rather than my brother trying to predict what he thinks will happen," (Y/n) said, looking at her partner. "And I think he now understands that even though he does not like you, and maybe my taste in mortals should be questioned, I have to be the judge of my own life."
"He is a good brother," Childe said, thinking about what it would be like if his little siblings were in similar situations as (Y/n), and him as Zhongli. "He wants to make sure you are happy and that you are safe."
"You're speaking as an older brother, aren't you?" (Y/n) asked him, smirking a little.
"You know I am."
(Y/n) smiled, and scooted a little closer to Childe, and was about to rest her head on his shoulder to relax, before a pillar suddenly appeared under Childe, and shot him up into the air, and into the water.
(Y/n) looked behind her and up near the terrace area, and saw her brother standing there, arms crossed, and not happy.
"Not cool!" (Y/n) yelled as she went off to go find Childe.
"You alright?" (Y/n) asked as she put some bandaids on Childe's wounds that he had obtained when he was shot into the ocean. The two had taken refuge near the border between Liyue and Mondstadt.
"I am alright," Childe chuckled. "I fought you and survived, so I don't believe there is anything that could kill me."
"An overprotective brother who was once an Archon could," (Y/n) said, putting a bandaid on one of Childe's cuts. "I am the younger twin, and we are on equal power levels, but when he feels like he needs to protect me, he is much stronger than me. You should have seen him during the Archon War. There were gods who had threatened to take my life, and then they were gone in an instant because my brother made them disappear without a single trace being left behind."
"How do you know they're dead now?" Childe asked.
"Zhongli admitted it after 400 years of their deaths..." (Y/n) mumbled.
"He is quite scary." (Y/n) laughed nervously.
"He's not around here, is he?" Childe asked, looking around.
"He probably is, why?" (Y/n) asked, looking around to see if her brother was anywhere nearby.
"Because I wanted to do this." Childe said, giving (Y/n)'s cheek a soft kiss.
A large stone suddenly landed on Childe's head.