The Great Onyx is a disposable in the Metal Shadow universe. It is a great lance created and once maintained in the depths of Agency HQ. Lad Wydnie stole it from the base before the base was destroyed. After he died, it fell into Anikae Shyrlie's possession.

The lance was created using Noa Rylie's DNA. It is the tool used to forge Agent jewels. It is a counterpart to The Great Zircon.