我是你致命的毒药我是你救命的解药
[wŏ shì nĭ zhì mìng de dú yào wŏ shì nĭ jiù mìng de jiĕ yào]
This indicates that the person believes they can be both harmful and beneficial to someone else. They play a complex and essential role in another person’s life—acting as either poison causing harm or an antidote providing salvation.