你生命中的那只招摇蝴蝶
[nĭ shēng mìng zhōng de nèi zhĭ zhāo yáo hú dié]
Referring to 'The Flamboyant Butterfly in Your Life', this might be used to describe an impactful yet transient presence in one's life, much like a butterfly which appears suddenly, adding color and beauty before leaving.