让你恨我是第520个任务
[ràng nĭ hèn wŏ shì dì 520 gè rèn wù]
In Chinese internet slang, 520 is pronounced similar to 'I love you'. This username humorously means that making someone hate him/her is his/her 520th task, suggesting a lot of past tasks were likely to be annoying others as well. Maybe he's been doing things to annoy someone or to win some games by defeating someone.