Kasotsu "acquired" these weapons from Keiz's armory while poking around. He has the strength to wield them, and they seem to fit with his fighting style(s). The fashion of these weapons comes from a long forgotten colony of Shrews who used special sigils and ores in their weapon's designs, giving them special properties and near a unbreakable blades.
Thunkydrus: The Thunder-Breaker: A 2-edged broadsword type blade of the sky-tribe's design. The blade is heavier, better for slower, yet higher damage dealing attacks. This sword's ability is Devastation. Upon contact with any surface or enemy, the blade unleashes a burst of energy, which tends to have a crushing power to it, giving the sword a higher impact and destructive capability.
Skyra-gyra: The Cloud Cleaver: A singled-edged broad sword of the sky-tribe's design. The blade has moderate weight, used for moderate speed attacks with moderate damage. This sword's ability is Resonation. Upon resonating energy from the user, the blade tends to vibrate, giving it extra slicing ability as well as adds special abilities from the type of energy used: ie, if wind based energy was used, it would have more slicing ability and have the ability to unleash cutting wind blasts when swinging the blade.