Even though, strictly speaking, Luo Binghe couldn't really be regarded as the one who killed him, but Shen Qingqiu indeed self-destructed and died in front of him. Ming Fan and the crowd of disciples behind him all drew their swords, ready to strike. Liu Qingge said, “You all cannot defeat him.”
Ming Fan drew his sword against his shizun's killer, but Liu Qingge stopped them. He told the disciples that they would not be able to defeat Luo Binghe. While Luo Binghe did not kill their shizun, Shen Qingqiu died for him and had to be avenged.
Shang Qinghua usually calls Mobei-jun 大王 (dà wáng), meaning great king, though it's often translated as my king.
This activated the mysterious System who transported him to the world of Proud Immortal Demon Way as Shen Qingqiu, Luo Binghe's teacher and the master of the scholarly peak, Qing Jing Peak.
With Luo Binghe going down the Endless Abyss being presented as a crucial event, it seemed inevitable that he'd turn into the cruel, sadistic Bing-Ge of the OG novel but Shen Qingqiu greatly underestimated the lasting impact his kindness had on Luo Binghe, who fell in love with him due to that.
Shen Qingqiu (沈清秋 Shěn Qīngqiū), birth name Shen Jiu (沈九 Shěn Jiǔ), is the original owner of the body that the main character; Shen Yuan transmigrated into after his death.
Luo Binghe (洛冰河 Luò Bīnghé) is the protagonist in Proud Immortal Demon Way, and the main lead in Scum Villain's Self-Saving System. He is half Heavenly Demon and half human, and was a disciple on Qing Jing peak taught by Shen Qingqiu.
Does svsss have a happy ending? Yup.
Mobei-jun (漠北君 Mòběi Jūn) is a side character in Proud Immortal Demon's Way and in Scum Villain's Self-Saving System. He is the ruler of the Mobei Clan (漠北, Northern Desert). His name is technically his official title, which is inherited by each ruler of the Mobei clan; if he has a birth name, it is unknown.