Ian needed Magic Beast materials with two key traits: "earth attribute" and "digestive system."
This was actually a very common combination.
For example, Elder Pude's bloodline inheritance, the "Crouching Rock Bear Lizard," was an earth-attributed Magic Beast. Its defining trait was its extraordinarily powerful digestive ability—it could even strengthen its carapace by devouring metal veins, or transform its entire body into steel-rock material. When it lay prone on the ground, it looked just like a great chunk of steel rock.
Other earth-attributed Magic Beasts were similar. Reef-Eating Sea Otters gnawed on Fortress-Building Coral, while Ironclad Sharks, despite living in water and being able to manipulate currents, relied on earth-attributed Origin Matter for the self-strengthening aspect of their abilities.
All of them possessed powerful digestive systems to ensure the sturdiness of their bodies.
"Here, we have a Stonewing Goose's 'Grinding-Wheel Stomach,' a Sickle-Armed Giant Bear's 'Strong-Acid Gland,' and a Needlefire Ant's 'Corrosive-Acid Sac'..."
Elder Manyan led Ian into the heart of the mountain. They passed through a long rock corridor and rounded countless bends before the space suddenly opened up deep within the mountain, revealing an enormous storage room.
The storage room was supported by arch beams made of Ruststeel and metallic braces, forming a semicircle. It was unusually cold inside. Most of what was stored there was food such as dried meat and rations, along with quite a few plant materials resembling tea leaves and medicinal herbs.
This was clearly an important storage center for the Avude Tribe. At the edge of the semicircular storeroom stood a sealed cabinet, from which Elder Manyan counted out Magic Beast materials stored in various jars and stone boxes.
"Oh, there's also a Deepsea Elder's—that is, a Magnetic-Wing Albatross's—'Metal-Eroding Gland'... But unlike the giant bear's Strong-Acid Gland, which produces highly acidic saliva, the Deepsea