The word 借刀杀人 is formed by the direct sequential combination of four characters: 借 (borrow), 刀 (knife), 杀 (kill), and 人 (person). This arrangement creates a literal action sequence meaning "borrow a knife to kill a person", where the first two characters establish the means (borrowing a knife) and the last two specify the act (killing a person), resulting in a cause-and-effect structure that conveys the core concept of using another's resource to inflict harm.