Hringhorni

Hringhorni is a location in DARLING in the FRANXX. It is an important construction project closely supervised by Papa and the Sages.

In Episode 20, Dr. FRANXX describes it as "a massive spear built using klaxosaur cores". Inside it is a massive weapon called the ‘Star Entity‘. Papa says construction on it is almost complete and it will save humanity. Hiro and Zero Two are tasked with taking control of it.

In Episode 21, the Klaxosaur Princess, after forcing Hiro to link with her, attempts to take control of it but she is infected with a virus planted as a trap by Papa. Dr. FRANXX tells Zero Two that she was created to operate it on behalf of the human race. Hringhorni is revealed to have been implanted with a self-destruction bomb by Papa that will destroy the entire planet. However Hiro and Zero Two stop it and Papa, along with VIRM, takes Hringhorni with them as they flee.

In Episode 24, VIRM uses Hringhorni against Hiro and Zero Two to severe their connection but they reconnect and take control of it, eliminating many VIRM armadas and sacrficing their lives to destroy the VIRM  planet.

Etymology
In Norse mythology, Hringhorni is the name of the ship of the god Baldr.

Trivia