Thunder Sabre (雷光衝破突, Sandā Sāburu) is a technique utilised by Ranke by drawing energy from the Stone of Gelel.
Ranke collects a large amount of lightning energy into her hand using the Gelel source in her body, balls her hand into a fist and strikes at her opponent. It was powerful enough to punch through Gaara's Shield of Sand and send the young shinobi crashing through a wall.
Although the Japanese subtitle of this technique is written in kanji, it is pronounced in English, "Thunder Saber" (サンダーサーブル, Sandā Sāburu). The Japanese pronunciation of the kanji would be Raikō Shōhatotsu, which would literally translate to "Flash of Lightning Collision Break".