为你孤独终老为你独守空城
[wéi nĭ gū dú zhōng lăo wéi nĭ dú shŏu kōng chéng]
This username expresses a deep devotion to someone, where the user is willing to live alone all their life and guard an empty city for that person. It's filled with a sense of unreciprocated love or a promise of unwavering loyalty.