The name Orcust may be a portmanteau of "orchestra" and "locust", referring to their endless numbers in the archetype's lore; it may also be a reference to Orcus.
This archetype's Japanese name is a reference to Orpheus and Orgel (the Dutch/German/Japanese for music boxes).
The Main Deck members are named after musical elements and have aspects of musical instruments as part of their bodies.
The Two Knights’ Differences Collide
The “Crusadia” fellowship arrived at the place where the final battle would likely be fought. However, what awaited them was the “Orphegel Army”. The true identity of “Longirsu” is that of “Ningirsu" who severed the bonds of friendship with his former friends and disappeared with his own goals in mind. “Orphegel” is an army of machines he created to achieve his ultimate goal. The “Orphegel” continue to ceaselessly appear from “Babel” and prevent the “Crusadia” fellowship from getting any further. These two former friends now wage a fierce battle against one another.
The Main Deck monsters all have effects to banish themselves from the Graveyard to Special Summon other "Orphegel" monsters from various locations, but prevent the player from Special Summoning monsters except DARK monsters for the rest of the turn. The Link Monsters all have diagonally opposing Link Markers, any additional Link Markers are on the Top or Bottom. The Link Monsters each have an immunity effect when linked, and a second effect that must be activated by returning banished Machine monsters to the Deck.