A short observation/thought regarding the title of the Fourth Anguis.

In Sen III we learn the title of the Fourth Anguis is 《千の破戒者》(Sen no Hakai), which directly translates to “One who broke a thousand religious commandments”. If we take “religious commandments” at its simplest terms, it could refer to the Ten Commandments, one of which is “thou shall not kill”. Considering the Fourth Anguis is said to be an assassin, I feel that it would make sense for their title to simply refer to “One who has killed a thousand people”.