Sloths are typically seen as a slow and lazy species. However, due to mutations triggered by blue crystal, the mountain sloths evolved a Xenoluce . Chimerizing with ape-like characteristics, they have transformed into agile creatures.  After ingesting aether energy  (blue crystal energy), they can climb and defend with incredible speed and strength, becoming a chimera known as the Megalith Sloth.
　　As the Vecks developed a modern mass-produced version of the pseudo-Ymirus mechs, the Karstenians also began searching for large units that could break through enemy front lines. Eventually, following the example of their Sand Lizard allies, they began domesticating chimeras as a last resort, to expand their assault capabilities.
　　That’s when the Megalith Sloth, a climbing chimera, became their best option. Since they lacked the tradition of rearing chimeras, the Karstenians opted for a simpler and cruder method, inserting controllers into the Xenoluce to operate the sloths. Instead of feeding them natural aether -containing feed, they had them carry energy canisters (Y-thermos) on their backs, supplying energy directly into the Xenoluce via tubes. This greatly increased the ferocity of the Megalith Sloth.
　　Thus, an exceptional military organism dubbed the Military-Grade Megalith Sloth was created. Capable of quickly scaling defensive fortifications, penetrating mountainous areas too challenging to heavy-armored units, confronting enemy light infantry with its size advantage in difficult terrain, and carrying a machine gun mount on its back, allowing its operator to unleash suppressing firepower, and even engaging in hand-to-hand combat using its limbs and cudgel. Armed with a aether -charged spear at its back, it can fling a projectile at adversaries within medium range.
　　“Mountaing such a creature? It flies in the face of a knight’s ethos…” Yet the Karstenian knights are unwilling to ride such unrefined creatures that do not showcase the air of a noble knight, leaving them to be handled by common-born assault troops. This has created a more flexible assault unit, agile and indomitable.