I AM NUMBER FOUR

I am reading a book called "I am Number Four." It is about a teenage boy who is from outer space. His species is being hunted down by other aliens called Mogolians. Numbers show up as scares on their skin  when they are next to be killed. His species are wanted for their powers so they are killed and the powers that they possess are obtained. The teenager flees with his protecter to earth. The Mogolians are not far behind them. This young man must use his powers for good and for his species, but he does not want earthlings to think he is strange.