Summoned to be a Weapon

Twin sisters Kate & Lina were just supposed to be going on a family vacation with both their parents for the first time in a while. They however ended up flying together alone on a plane ahead of their parents because of a booking error.

Things were going smoothly as it was a perfectly fine day for airline travel without a single cloud or obstruction to the path of the airplane. Without warning lightning struck the plane, and when everyone thought they were going to be electrocuted to death they opened their eyes to find out that they were transported to a new world.

Arriving in the unknown world, they quickly discover that while they might have gotten a unique ability that allows them to stand out among the people of this unknown world. However unlike the various isekai series(both new and old versions) that a lot of them were aware of, they did not have any knowledge nor experience to use even the most basic of basic skill or magic native to this world. Since they were unable to do even that using their newfound ability was an impossibility for them entirely. They had power but no way to properly use even a fraction of it on their own.

They soon came to know that they were not transported to this unknown world by accident or coincidence, but they were indeed summoned. The purpose they were summoned for, and the reality they were facing differ from the stories.

They were not summoned...

to be heroes as there was no threat human or otherwise. Conflicts and wars were something they could handle themselves

for their work as even the the lowest rank solider and/or adventurer were better.

even to be ultimate weapons as those in power already had those already

They were summoned to be mere weapons that anyone could gain access to a long as they met the requirements. Their summoning was just them acquiring a new batch of weapons to made and used nothing more and nothing else.