万年隐身攻千年在线受
[wàn nián yĭn shēn gōng qiān nián zài xiàn shòu]
This is a humorous play on words derived from BL (Boy's Love) fandom terminology. '万年隐身攻' refers to someone who is always 'invisible' in the dominant role, possibly implying being shy or unapproachable; while '千年在线受' means someone who is always available online and in the submissive role, possibly meaning they're always present but not in charge. It suggests a playful or self-deprecating take on one's online persona.