This is a two side blade, capable of harming mortals or monsters. I made this for school. Please do not report me this is not violent and yes I know a sword is a weapon.
Aequormons: Aequormons, a double edged sword, whose name translates to Seamount (seamounts are underwater volcanoes). Aequormons, at first glance, looks like a pen, but when uncapped, it transforms into a sword. It has both stygian Iron and celestial bronze, forced together. They naturally repel each other, but when forced together, they can harm mortals and monsters, demigods, and other mythological beings. The pen also returns to your pocket when you lose it, though it takes a few seconds to return. Simply place the cap on the tip of the sword and it will shrink down to a pen. This sword works especially well for children of Poseidon or Vulcan, but it can head to whoever is strong enough. Aequormons is currently non-existent, but if you got excited and were hoping this sword was real, maybe Hephaestus’s children can help you out. This is only a sketch and does not possess any existence besides being on a paper. Hopefully, you are a mortal that has absolutely no interest in buying a sword and have not gotten hooked by this fake marketing.