Also known as the HTB Cannon (Hyper Tronium Buster Cannon). Combination attack with R-Gun Powered, where the R-Gun Powered transforms into its Metal Genocider Mode and is used as a giant gun by SRX. Power from the SRX's Tronium Engine is synchronized with the R-Gun Powered's own Tronium Engine at 120%, as the trigger handle for the weapon emerges in front of Ryuusei in SRX's cockpit. Taking hold of the handle, Ryuusei cries "Ichigeki Hissatsu! Buster Cannon!" (一撃必殺！バスターキャノン！ | One-Shot Certain Kill! Buster Cannon!), followed by the gigantic Super Robot blasting the unfortunate enemy to smithereens (usually all the way to the Sun in Dynamic Kill animations). In Super Hero Operations, during the final battle against Chouj.