Dead Sun - Advena Swords

Extremely long, sting-like swords, the main weapons of the advenas, which they usually double wielding. Even though these aliens have highly evolved technology, for some reason they prefer a simple-melee weapon such as a sword, because it lets them utilize their sheer muscle-power. This way they can take out the human soldiers silently, and strike in their vulnerable parts with much more precision than any long-range weapon. But since the length of the swords creates a difficulty at carrying them around, they had to make them be able to fold back into a shorter, more compact mode in and out, allowing them to put the sword back into a relatively smaller sheath.