The demonic sigil is a staff made and used during the Shadow of the Storm quest. It is made by using a silver bar on a furnace with a Demonic sigil mould in your inventory. The player using it must chant a combination of the words as shown in the Demonic tome to summon the demon Agrith-Naar. The game does not allow you to make this item after the quest is complete.

After the quest is complete you can use the emote to chant using the Demonic sigil, chanting the five words in any order you want. This has no effect and will not summon a demon.

There is currently a glitch where if you chant any of the words then quickly do an emote any effects will be visible without your avatar doing them.