The Great Giant Monster Plan

Everything that Zorori has tried has failed. The kids are impossible to scare. The only ghost that hasn't tried scaring them yet is Oonyuudou, but he is so small and not very scary. But Zorori has a plan. He's going to construct a giant robot that looks like an oonyuudou for Oonyuudou to control. Will this plan work or will it fail to scare the kids once again? Based on book 17.