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/Organs).
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 “Orcust 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. “Orcust” is an army of machines he created to achieve his ultimate goal. The “Orcust” 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.
Although their Link Monsters effects are quite situational by themselves, with their Field Spell Orcustrated Babel their effects become powerful Quick Effects that can interrupt the play of decks, especially heavily Link-based ones. This also alleviates their once per turn Summoning, allowing them to Summon twice as often. For their Link Summoning, like Crusadia, they favour a "ladder" strategy, where each Link Monster is used as Material for the next one, however, unlike Crusadia, this is not (near) compulsory. Orcust Cymbal Skeleton makes this option even deadlier by allowing you to revive the Link monsters used as Material later, so that while you start with one powerful monster, you can easily build up a strong board. In particular, Longirsu and Orcustrion can be both immune to the effect of Topologic Bomber Dragon while Linked to it, whose effect can be triggered by the Quick Effects of the Main Deck monsters, giving you near-total field control. While keeping up the supply of banished monsters and not running out of resources is difficult at times, the deck can recover from most setbacks surprisingly well.