You can craft it. Same as many other element weapons after getting the recipe at the monsterhall in your castle.
Not every weapon type has a weapon for every element.
You get the "Monster Craft Recipe" from Vivian after she moved to the monsterhall. In order to construct the monsterhall, you need to finish the events about Soul Lanterns at Whisperwind Farm in Begus, and then talk with Sir Edward in your throne room to get the option to construct the monsterhall in your castle.