Ji Bozhang wanted to use the Howling Celestial Dog as a direct substitute, especially since he held dirt on it. By exploiting this leverage, he could coerce it into acting as "fertilizer" with explosives planted inside its body.
Once the job was done, they would simply kill it.
That way, Si Ren would bear no infamy, and Liu Ruxue would not have to sever her own arm—a win-win for everyone.
Chapter 1265