bàn lù shā chū gè Chéng Yǎo jīn
lit. Cheng Yaojin ambushes the enemy (saying)
fig. sb shows up unexpectedly and disrupts the plan
sb whose presence is regarded as irksome
Chéng Yǎo jīn
Cheng Yaojin (589-665), aka 程知節|程知节[Cheng2 Zhi1 jie2], Chinese general of the Tang dynasty