oh, thought you said you wanted fantasy and sci fi. misread it. but the point was theres a huge selection in sci fi. steins;gate is about time travel. death note is about a child who gets a book which has the power to kill then uses it to take over the world. code geass is about a child who gains the ability to control people's minds and uses it to take over the world. etc etc

Thanks xD But not really interested in manga.