All people have a double of themselves, a sort of parallel dimension twin that only exists in the frontier between reality and fantasy, a ''Doppelgänger''. However, recently these doubles have managed to finally cross into our world and when they encounter the person they take from, both will be transfported into the ''Terror Zone'', a separate dimension where you and your doppelgänger will duel. When in that place, time will move faster, as one minute inside equals to one second outside.
A Doppelgänger not only is a ''darker version'' of yourself, but it also incarnates both your desires and fears, allowing it to use those factors to overpower the original, that being you. If you manage to kill it or make it admit defeat, you'll become an ''Übermensch'', being able to transcend regular humanity and obtain a special power that will allow you to fulfill one of your desires, as well destroy your fears. Not only that, to really remark your evolution as a human being, you receive Peak Human Body as a bonus gift. However, if the doppelgänger manages to defeat you, it will possess your body and become similar to an Übermensch, but lacking any empathy for regular humans, using its powers to self-indulge on a hedonistic lifestyle.
Could you defeat ''yourself''? What is the power that you'll gain? Will you fight against the doppelgänger invasion? Also, I must say that to prevent the universe from being destroyed, the powers gained by Übermensch and Doppelgänger cannot allow one to alter the past, bring back the dead or summon fiction into reality.