[魔高一丈,道高一尺, mó gāo yī zhàng, dào gāo yī chǐㄇㄛˊ ㄍㄠ ㄧ ㄓㄤˋ, ㄉㄠˋ ㄍㄠ ㄧ ㄔˇ] the devil is ten foot tall, virtue one foot (成语 saw); It takes constant vigilance to stave off evil.
[しんたいりょうなん, shintairyounan] (n) being driven to the wall; finding oneself between the devil and the deep blue sea; finding oneself between a rock and a hard place