also: りょうばのけん
double-edged sword
Idiomatic expression meaning something that has both advantages and disadvantages, or can be both beneficial and harmful.
The internet is a double-edged sword. While convenient, it also comes with dangers.
His talent was a double-edged sword, bringing success but also causing friction with those around him.
Mixed kanji-kana spelling; もろ刃 is a common way to write 諸刃.