The Sidecar Glider is an aerial vehicle that appears in Kingdom Hearts II and Kingdom Hearts II Final Mix. Riku commandeers it in The World That Never Was for the second battle with Xemnas on the Altar of Naught. It is only seen during the battle against World of Nothingness.
After the Corridor of Darkness leading to Destiny Islands closes, Xemnas appears along with the World of Nothingness to attack Sora and Riku. After it destroys part of the upper tower of the castle, Riku notices the Glider and runs towards it, and tells Sora to hop on. The two then continue to follow Xemnas on the Glider until they face him in the ship's cockpit, and the Glider is sucked into a void of nothingness.
The glider is similar to sidecar motorcycles, where a small cab is attached to the relatively larger main vehicle in order to provide for a second passenger. It shares many similarities with Terra's and Ventus's Keyblade Gliders. Like Terra's glider, Riku's glider is sharply angled at its front tip, and the seats in both are slung forward so that the driver is nearly horizontal. The sidecar, like Ventus's glider, has the passenger standing up and unrestrained, allowing them to strike passing enemies.
The Megalaser is a Reaction Command that can only be activated after filling the Megalaser bar by using Drain to convert the offensive small lasers from enemies into energy.
When Riku uses this command a barrier is created, similar to Aqua's Reflect barrier, this feature allows you to absorb some of the energy from oncoming lasers to charge up the energy meter so that you can use the Megalaser Reaction Command. It also reflects some of the energy at Xemnas's ship. It is used by pressing .
Commands Sora to strike with his Keyblade. Sora will do a 360-degree horizontal slash. This attack is used to hit bomb-like Nobodies, but can also hit enemies that fly too close. If the Nobodies are hit, they'll be thrown into the ship's part, dealing a good amount of damage. Riku uses it automatically when the Bomb Bell Nobodies appear. It is used by pressing .