How did Brainiac take control of Warworld in "Panic in the Sky"?

[tib2d2]

I can't recall how Brainiac was able to be in control of Warworld in the Panic in the Sky story arc. And where was Mongul?

[sunofdarkchild]

Mongul was still in exile after Superman defeated him, and Braniac exploited the power vacuum to take control. Once he hooked his mind up to Warworld's systems the station's power amplified his psychic powers exponentially and made him unstoppable so no one could oppose him.