Nephilim are powerful creatures. They are immortal and unkillable except by angelic intervention and perhaps demonic powers, they have the ability to manipulate other people’s emotions by instilling them with sin and they can feed on the sin of others.
When choosing a Sin, find one that you are comfortable playing. The Nephilim are not entirely defined by their sin but it is an enormous part of their life and once chosen it cannot be changed. You will often feed in similar locations to other members of your tribe, but you still need to be careful when meeting lest you accidentally trigger an angelic hunt.