Starkiller Base

Starkiller Base was a massive mobile First Order military installation and superweapon constructed into the planet Ilum. Easily one of the most formidable superweapons ever deployed within the galaxy, Starkiller Base was a fusion of the kyber-based superlaser technology used by the Galactic Empire in their Death Star battle stations, and reverse-engineered Rakatan technology provided in secret by the Mallus Empire. Consuming stars as a power-source much like the ancient Star Forge, Starkiller Base could decimate entire star systems by firing massive energy beams through so-called "sub-hyperspace", which could then split upon entering realspace to target multiple planets. The installation also served as a massive mobile command center for the First Order.

Starkiller Base was only ever to showcase its incredible power a single time, when it was used to destroy the Hosnian System at the outset of the Second Galactic Civil War. Months later it was planned to be used to destroy the Castilon system, but was destroyed in a daring raid by resistance forces from the New Republic Remnant.