The Royal Onyx Helmet is a standalone armor piece that can be obtained in the Frontier. It can only be acquired as a rare drop from the Ancient Onyx Knight. There are no alternative methods to acquire the Royal Onyx Helmet outside of its main source.
In appearance, the Royal Onyx Helmet looks identical to the Onyx Helmet, except it possesses a purple plume at the top of the head, similar to the 'royal styles' shared among the other Royal Helmets.
Once equipped, the Royal Onyx Helmet will provide 9 armor points, slightly increasing the player's protection. Other than that, it does not have any beneficial usages other than to be used for vanity.
- The Royal Onyx Helmet is one of the few Royal Helmets that remains unaffected by any updates from the Otherworld Update to the Ratboy's Nightmare Update.