Riku explained to them that even though he was the creator of the gun and landmines in this world. Still, he hadn't had the decision if he was going to supply the Colonary Kingdom. Well, collecting the ingredients for the landmines wasn't that hard, yet, he had a lot more stuff needed to do, and making thousand of guns can take a year, which was not good for his domain quest.
Apart from that, Colonary Kindom was already a powerhouse as no one kingdom in this world could easily invade them. Given the magical knights are powerful, royal guards, as well as the King thay can seem to destroy a certain mountain with just a click of his finger.
