Koenma - Primed with the Mafukan! Yu yu hakusho : Season 3 Episode 87

As Itsuki explains more about the bizarre Sensui, Koenma prepares to use his most powerful weapon: his pacifier! It can create a barrier that would stop the demons from flooding Living World. Koenma knows that Sensui must be stopped or his evil plan will come to fruition dooming the entire human race!