As the name would suggest, these Ethereal Blades are stiff, unfoldable fans with long handles. The handles are pale yellow, while the upper halves are purple, with a small gradient blending the two colors at the middle. These Ethereal Blades do not glow.
Landing a strike with the Round Fan creates a shockwave of air around the target. Landing a combo finisher creates a larger, doubled shockwave.
A round fan (団扇, Uchiwa?) is a traditional Japanese handicraft made by cutting a bamboo tube into narrow splinters and splaying them out in the radial shape of a fan, then pasting paper over them on both sides. They were widely used among ordinary people in the Edo period.
Its design likely refers to how Xemnas "fans the flames" of Master Xehanort's plans.
The ground combo consists of a single slash from left to right, a spin ending in a double slash, and a double spin ending in a double slash with knockback.
The aerial combo consists of a quick upward spinning slash, a double spinning slash, and a quick spin with two more slashes.