Link had plenty of materials on hand. Previously, when the Beastman Warlord commissioned Link to craft his axe, there were many leftover materials. There was plenty left to craft a magic sword.
Link once crafted a Khorium sword for Kanorse. Kanorse had provided Link with the design for the sword, so it was very simple. Therefore, right now, based on a similar design, all Link needed to consider was the magical component of the sword.
After thinking about it for a while, Link decided to use talismans to inscribe the sword with magic. He had plenty of experience with using talismans, and based on his experience with it, he could create profound effects.
He had a few high-grade talismans with him, ones that he had gotten from High Elf Lord Derrac's Lightning Wand.
He took out one lightning talisman from his dimensional pendant.