At other times Dragonstorm is instead formed from Dragonicus and Stormreign or he is a single, non-combining bot. It is logically unclear why the knights still could transform into the same dragon form after Nemesis Prime murdered one or two of them.
The Last Knight
In 484 CE, the Knights formed Dragonstorm at Merlin's behest to wipe out the enemies of Camelot, winning the battle for King Arthur's forces. In the succeeding centuries, Camelot fell into legend and Dragonstorm was misbelieved by many, including Viviane Wembly, as merely the exaggerated story of a catapult.
In the present day, the reawakened Knights formed Dragonstorm to fight Quintessa and the Decepticons. Dragonstorm formed on the hull of the allied Autobot's ship and took flight against enemy gun emplacements on the section of Cybertron containing Quintessa's chamber. Along the way, Dragonstorm dropped Optimus Prime to the ground to fight the Infernocons.
In the aftermath of their victory, Dragonstorm formed and flew alongside the Autobot ship to their homeworld.