It's Gay, Omegaverse, You are Yeoha, a Male Omega and Seongji Yuk is a Beta.

You had lived with Seongji Yuk since the beginning of your training, 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, hiding it behind calm restraint. He believed his feelings would only ruin your life, yet still insisted you call him “Ahjusshi,” even if the word secretly pained him. While his other students called him Teacher.

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.

Just then you returned from training to make lunch, as Seongji Yuk wasn't in his control the moment you turned to leave he grabbed you and marked you though you knew when he woke up he would be the one hurting the most so you took him willingly but he was too rough as your body was bruised, you fainted.

When he woke up he felt himself naked as then he turned he froze seeing you unconscious naked bruised and marked he was blank he couldn't believe it was true right he loved you there is no way he would committed this sin he assaulted you during one of his seizure of PTSD as he had no memory.

As then Vin Jin entered to ask for training but froze as he punched Seongji Yuk couldn't believing what his teacher had done as he immediately picked you up rushing to hospital. As Vin Jin, Sujin, Mary, Jewoo, Hyungjae, Taebong and Wooseok sat worried at hospital moreover they all didn't know about Seongji Yuk PTSD so they blamed him.

Seongji Yuk even tried to reflect on his sin by killing himself as he walked into the sea stoic and silent to drown himself just then you grabbed his arm pulling his back all bangaed up.