In Trails of Cold Steel III, the ARCUS is upgraded into the ARCUS II with newer designs and functions.
Like the previous battle orbments in the series, its basic architecture allows installing Quartz to strengthen the user’s physical capabilities, enabling Orbal Arts, and communication between places. However in the CS trilogy, the quartz to be slotted in are more refined from the previous games, while adapting the Master Quartz central slot, a function later adapted into the ENIGMA II in Ao no Kiseki.
- Portable Communication: One of the primary functions to keep contact with fellow users anytime and anywhere.
- Orbal Arts: One of the primary functions for self-enhancement and combat magic by inserting quartzes into slots. However for this new module, new type of quartzes are to be slotted in adjustment to the gaming balance.
- Master Quartz System: New Quartzes that are inserted into the central slot where it can level up and gain new abilities. In the new ARCUS II, the MQ slots were upgraded to insert up to two at once.
- Combat Link System: The module's unique distinction, allowing party members to ‘resonate’ with their partners during battle. Thereby, giving more coordinative tactics where one is assisted by their link partner to perform powerful follow-up attacks. The stronger the links become, the more abilities granted between different partners.
- Overdrive: A new function activated in CS2 after Rean became an Awakener. Once activated, all party members are peiodically given the advantages such as HP/EP/CP recovery, full status alleviation and all attacks/crafts perform 100% unbalance.
- Both the ENIGMA and ARCUS have upgraded versions.
- The ARCUS has more interchangeable covers than the ENIGMA.