I noticed that there wasn't a tag for this type of hula hoop-like blade that Tira is known for using, although Mouri Motonari also uses it. In fact I was looking for this type of tag while doing some Sengoku Basara uploading.
They're the only characters I know of who use this weapon, but if there isn't a tag, I'd +1 the creation of a ring blade tag, and of course the weapon implication.
I also think this is different from chakram because those are smaller and tend to be wielded in both hands, whereas this is a single, full body sized weapon.
Updated by ion288