|This article is about a/an weapon in Kamen Rider Den-O.|
The Nega DenGasher (ネガデンガッシャー Nega Dengasshā) is modeled after a bullet train and is Nega Den-O's primary weapon. The Nega DenGasher is composed of four separate parts that, when not in use, are attached to the Den-O Belt. As with Den-O, Nega Den-O can use the Nega DenGasher in all four of its combinations while in Nega Form. And as with Nega Den-O's armor, the Nega DenGasher's blade is purple with cyan tribal markings.
- Sword Mode (ソードモード Sōdo Mōdo): The Ax and Gun parts are stacked on top of each other, forming the center of the sword. Then by throwing the attached part in the air, the other two parts are held out, and electricity catches and links them together. Afterward, a blade extends from the Sword part.
- Rod Mode (ロッドモード Roddo Mōdo): The four parts are linked together in a vertical line, one by one, in the order of Sword, Gun, Ax, and Grip. Once complete, the DenGasher extends itself until it reaches the size of a typical staff. Though usually used as a spear, the blade can also be released on a wire, functioning as a fishing rod.
- Ax Mode (アックスモード Akkusu Mōdo): The Grip and Gun parts are stacked on top of each other, creating the handle. The Sword part is then attached to the handle, following it, the Ax part is attached to the side, containing the blade. The blade then extends and expands.
- Gun Mode (ガンモード Gan Mōdo): The Gun part from the left side is tossed in the air. Then, the Sword and Ax parts on both sides are stacked on top of each other. The Grip is attached to the bottom of this, while the Gun part falls into place, forming the barrel.
- Nega Wild Shot (ネガワイルドショット Nega Wairudo Shotto): Nega Den-O charges an red energy ball an shoots it from the Nega DenGasher.