Dimensional Cannon

The Dimensional Cannon (次元砲 Jigenhō) will bring chaos to Earth! When it finishes its recharge time of 300 hours.

Fiction

Super BomBom comics

Galvatron had the Dimensional Cannon affixed to the Decepticon's battleship headquarters. When the ship came in range of Earth, the Decepticon leader ordered it to be fired, but it happened to hit Rodimus Convoy Jr.'s ship as it emerged from warp and caused the boy Yūji to merge into his Autobot friend's being. Not knowing of their presence, Galvatron was baffled that nothing happened and ordered a retreat to let the cannon recharge. Rodimus Jr. Does His Part! Defeat the Legendary Evil Beasts