心软是最致命的脆弱
[xīn ruăn shì zuì zhì mìng de cuì ruò]
'The Soft Heart Is the Fatal Vulnerability' implies that being too sympathetic or soft-hearted can be regarded as one's most significant weakness. It may mean a willingness to forgive, tolerate, help, which could lead to hurt, betrayal, or loss, reflecting a person possibly suffering from it before.