人は4人、代価は…

You can use a friends Jingliu for this achievement. Recommended to use the Vomit Inducing Agent.

This achievement has no cultural references in the English and Chinese versions. It is specific to the game. The achievement cleverly plays on the line "Of five people, three must pay the price," frequently mentioned by Blade and Jingliu. Given a humorous spin, the achievement necessitates your Jingliu to bring an ally's HP down to just 1. Considering you can have a maximum of four characters in your party, it amusingly suggests: "Of four teammates, one must pay the price (to unlock the achievement)." It's a witty reinterpretation of the original line. - Credit: Fen