Guild Seal

"This Guild Seal is my treasure. You will not take it away from me!" - Hovernyan.

The Guild Seal is a large, disk-like object adorned with the symbol of the Heroes' Guild that symbolizes the graduation of a Hero. The seal also serves a practical purpose and is used by several characters in the Birth of the Nyight. As years pass, Hovernyan becomes the only person to use the Guild Seal.

History
Haruki Maruyama has one to communicate with the Guildmaster and to use the Cullis Gates. Briar Rose, Thunder and other Heroes constantly use it to teleport from one place to another. Scythe also used one, but not much is known what he used it for. It is known that he destroyed his when he travelled to the Northern Wastes. The reason for this is so that he wouldn't activate the Cullis Gates, thus preventing the traitorous Maze from following him.

There is also a variant used by the henchmen to teleport with you.

A second variant exists that is used to teleport guards and trainee Heroes into the battle to help Haruki when Jack of Blades is trying to activate each of the four Focus Sites in his attempt to reclaim the legendary Sword of Aeons.

In The Relic, it is revealed that Hovernyan is the only hero to use the Guild Seal. It is also used by Theresa to talk to the Hero. The Guild Seal is no longer used to travel around the world as now you are able to fast travel anywhere whether or not there is a Cullis gate.

For Darknyan and Venus Purple's Fear: End of Yo-Kai World, Hovernyan gains another seal that will transform Hovernyan into the Yo-Kai Hero. This in turn gives Hovernyan access to the Road to Rule, enabling him to meet Theresa, unlock his true power as a Hero, and learn of the need to start the revolution against Logan.

The Guild Seal once again functions as a communications device; Jasper uses it to communicate with Hovernyan, giving them important information.

The Guild Seal also allows the Hero access to the Reliquary, under the Brightwall Academy and becomes a Trophy in the Trophy room of the Sanctuary or a mounted house decoration.