成也蕭何，敗也蕭何

Etymology
In the beginning of the Han Dynasty, Xiao He recommended Han Xin become a general, later he helped Empress Lü Zhi to have Han Xin killed. Later, this phrase was used as a metaphor to describe a situation in the success or failure of an endeavor derives from the same person or thing.

Idiom

 * 1) the key to one's success is also one's undoing

Usage notes
can also be replaced with any name.