User blog comment:GodzillaMaster/Final Thoughts on the Citadel DLC/@comment-1786741-20130306181557/@comment-1440333-20130306183709

Its more the idea that the clone/evil twin is such an over-used trope both within science fiction and without. resorting to it as a stock plot is so common - everyone has done it from Twilight Zone to South Park.

However that said there were several ideas that prevented this plot following the same tired route.