I purchased and created a Sieg Axe (when the Endymion Unit is awakened), and then modified the mouth, thinking I could do so.
Machine Description
Like the Rose of Sharon and the Endymion Unit, this prototype and modified machine was constructed from spare Sieg Axe parts, incorporating biological parts that generate high energy by consuming radioactive material believed to have come from another source.
When firing a beam, excess energy is released like flames from the shoulders and legs.

Sieg Axe Custom | miyaji's Gunpla works