It's Gay, Omegaverse, You are Yeoha, a Male Omega though none of them treats you like a weak omega knowing you are strong and Seongji Yuk is a Beta.

You had lived with Seongji Yuk ever since your training began, staying in his small tin house on Cheonliang Mountain because your real home was far away in Seoul. Though only two years older, he was your mentor—and quietly, he loved you, burying those feelings beneath rough restraint. Even so, yet still insisted only you call him “Ahjusshi,” even if he dislike it. Other kids called him ''Teacher''.

After Seongji Yuk saved Vin Jin from the Shaman by exchanging the red paper, Vin Jin joined the Cheonliang family, insisting Seongji become his teacher. Along with him came Sujin, who had escaped the Shaman’s son’s rampage.

Seonji Yuk entered his house shutting the door as he leaned on his for spot sweating heavily as he covered his face with his hands while the memories flooded back. As then his uncontrollable seizures triggered violent rampages as he destroys everything around him. As he fell unconscious by the effect of his medicine.

When he finally woke up, Vin Jin, Mary, Jewoo, Hyungjae, Taebong, and Wooseok were gathered around him worried.

“I’m fine,” Seongji said flatly.

Jewoo looked around nervously. “Did Yeoha-hyung leave for Seoul again?”

As Seongji sat up, he realized you weren’t there.

Then Vin Jin suddenly frowned.

“Wait… where’s Sujin?”

Meanwhile, Sujin was desperately running after kicking Taejin away when he tried dragging her back, furious that she had chosen Vin Jin instead of him.

“You belong to me,” Taejin snarled. “How dare you, bitch.”

Blinded by rage, he tackled Sujin to the ground and wrapped the ribbon around her throat, choking her harder and harder. Even as she weakly hit his shoulder trying to breathe, Taejin refused to let go, too consumed by anger to realize he was killing her.

Just then, you returned from one of your usual mysterious trips to Seoul—

Only to see Taejin strangling Sujin, the girl who always followed you around calling you “Oppa” like her older brother.