Merciless
In Chinese, the Pinyin is w ú Q í n à sh à OMI à n, which means no affection. The source is the supplement to the journey to the West.
The origin of Idioms
The second chapter of the supplement to the journey to the West: "I've seen him several times, and I'm not a person who has no feelings for others."
Idiom usage
As a predicate, attribute, etc
Merciless
a tree has its root , a stream has its source - mù běn shuǐ yuán