|This article is about a/an transformation device/weapon in Kamen Rider Kabuto.|
The Sasword Yaiver (サソードヤイバー Sasōdo Yaibā) is Kamen Rider Sasword's henshin device, modeled after a mid-length Katana with a straight blade. By placing the Sasword Zecter onto the back of the blade's length, Tsurugi Kamishiro can transform into Kamen Rider Sasword. The Sasword Yaiver also acts as his personal weapon, enabling him to perform the Rider Slash attack, during which the blade secretes a potent poison.
When not in use, the Sasword Yaiver can be mounted onto Sasword's left leg.
- The name of Yaiver is a combination name of Yaiba (written in kanji as 刃) and Saber (written in katakana as セーバー) with yaiba meaning blade and saber meaning sword.
- However, the pronunciation of Yaiver is close to that of Yaiba.
- The Sasword Yaiver is the first transformation gear to be a sword and for a long time also the only one until the Zaia Slashriser .