Fallen Axe Raider is a Small Sized Aragami introduced in God Eater 3.
The following information can also be found via descriptions of the Aragami found in the NORN Terminal's database.
God Eater 3
A Fallen Axe Raider with skin that is softer than it looks. Unfortunately, it can emit searing heat from this hide and even use the blazing energy stored in its internal heat organs to empower itself, making it far more ferocious than normal.
Further observation has also confirmed that it can draw magma from the earth to induce small-scale eruptions.