The Dark Signer associated with Earthbound Immortal Uru has the ability to control spiders. That present day Dark Signer is Roman. By latching the spider onto a person, that person can be possessed.
As a Shadow Drone, the victim's Deck is changed to that more fitting of a Dark Signer. Such as including a Dark Synchro Monster. The Shadow Drone gains some Dark Signer powers, such as the ability to Shadow Duel. After losing a Shadow Duel, the victim and their Deck is returned to normal and they have no recollection of what happened while possessed.
After the Fortune Cup, the Dark Signers turned a number of people in Satellite into Shadow Drones and dispatched them into the streets to preach that the Crimson Dragon is evil. While other people, including Grady listened, spiders were lowered onto them, in order to possess them.
Trudge is turned into a Shadow Drone a second time, shortly after Yusei defeats Kalin. Through Trudge, Roman invites Yusei to come and face him. The spider then leaves Trudge, returning him to normal.