已千疮百孔还装作刀枪不入
[yĭ qiān chuāng băi kŏng hái zhuāng zuò dāo qiāng bù rù]
This translates to 'Though already full of holes and damages, still pretending to be invincible.' It describes someone who is internally vulnerable but acts tough outwardly. Despite being hurt many times, they maintain a facade of strength.