Name: "Magic Spark"
Origin:
"Magic Spark" is a legendary sword created by magical forces deeply rooted in the history of Skyrim. Its story is closely tied to the catastrophe known as the Great Collapse of Winterhold. This cataclysm not only destroyed a large part of the ancient city but also unleashed countless magical artifacts and powers, including "Magic Spark."
Legend and Creation:
Before the Great Collapse of Winterhold, the city was a center of magical study and research, surrounded by powerful mages and artifacts. At the heart of the city was the College of Winterhold, where the most secretive and dangerous magical experiments were conducted.
The sword was created by Arcanian, a legendary Archmage of the College, as part of an experiment to stabilize and harness the energy of the Dwemer artifact known as the Eye of Magnus. Arcanian was deeply convinced that the Eye could be the key to an immense power capable of altering the course of Skyrim's history. He decided to channel this power into a sword that could not only be a weapon but also a source of light, capable of opposing any dark magic.
Arcanian spent years engraving magical runes onto the blade and creating a weapon that could contain and control the immense energy of the Eye. After completing the sword, Arcanian named it "Magic Spark" because of its ability to release bright flashes of light that could cleanse dark magic and dispel darkness.
The Great Collapse of Winterhold:
When the catastrophe known as the Great Collapse of Winterhold occurred, the city was destroyed by a massive explosion of magical energy. Arcanian attempted to use "Magic Spark" to control the Eye of Magnus and prevent the disaster, but the power of the Eye was too great. The explosion caused enormous devastation, engulfing Arcanian and his sword. The city was ruined, and "Magic Spark" was lost in the magical chaos.
Location in Skyrim:
After the Great Collapse of Winterhold, "Magic Spark" was lost to the world. However, decades later, rumors about this sword began to spread among archaeologists and explorers. It was discovered that the sword remained buried in one of the ancient, magic-filled places—Mzulft, a Dwemer ruin in eastern Skyrim, known for its mechanisms and labyrinths.

You don't have to look for it in Mzulft, you can create a blade at the forge, but the price will be high.
I'll give you a hint. Maybe some falmer liked the sword and stashed it in a chest.

There are 2 types of blade one has static illumination of runes - it is needed to create a sword of shimmering runes it is what you can find in Mzulft.