So... fashion for Power Rangers villains?
I was knee-jerkingly aghast at conflating Ultraman and Power Rangers, but... no, they're basically the same thing.
Repository of All Human Knowledge:
Ultraman fires a saw-like Spacium-energy ring (a Cutting Halo (八つ裂き光輪 Yatsuzaki Kōrin)) from his hand. This Halo can slice his opponent in half. The Cutting Halo does have drawbacks, however; a Baltan alien was able to deflect a Halo with his barrier, Gubira was lucky enough to catch a second Halo on his nose rather than be sliced by it, and Keelar was just as lucky to catch a third Halo with his tail. Alien Mephilas destroyed a fourth Halo with his Bare Hand Beam, and a fifth Halo shattered after striking Zetton's barrier. In Ultraman vs. Kamen Rider, Ultraman used this to sever Sasori-Gadoras's tail after Kamen Rider 1 had been struck. (This was used against RedKing and Alien Baltan II, among other opponents.) In the Mebius movie, he used it cut Ukillersaurs' tentacles during the final battle. In Episode 47 of Ultraman Mebius (Urutoraman Mebiusu, 2006), Alien Mephilas was able to evade a pair of the halos Ultraman sent at him for a while, before shattering them with his bare hands.
Hope that helps.