The Realm Reactor is where Commander Keen's final battle will take place in Atroxian Realm!
Battling his way through The Sky Sanctum, facing numerous deadly foes along the way, Commander Keen at last climbs to the very top of the ancient building. Amid the pits of scalding blue flames and the blackened Krile statues that decorate the top of the Sanctum lies a giant blue crystal. This is the Realm Reactor, the massively powerful energy machine used by Atroxus to bring the evil Atroxian Realm to Planet Krisle. As Keen approaches the Reactor, a massive shadow hovers menacingly above him...
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