Of course, Nial had created the small runic armament by himself.
It was not a big feat as long as one knew how to engrave overlapping miniature runic constellations. Nial could do that as long as the overlapping runic constellations were not all Advanced Runic constellations.
However, the Royal Princess was oblivious to this. She still thought of him as a rather new Runicier, though with exceptional talent, unable to create something even Grandmaster Runicier had a hard time creating.
Nial was fortunate enough to be a unique Grandmaster Runicier, with a terrific mana affinity, decent knowledge as a Runicier, and the ability to visualize everything in his mind.