山盟海誓天长地久永垂不朽
[shān méng hăi shì tiān zhăng dì jiŭ yŏng chuí bù xiŭ]
'Vow by Mountains and Seas, Eternal as Earth,' is an extremely romantic username signifying everlasting love, unbreakable promises, and undying memory. It’s a poetic way to express eternal affection and loyalty, almost mythical in grandeur.