JunkieOverThe_Moon Ho!! an evil being!! You don't need to be an assassin to kill those friend's entire families, you just need to learn the art of arson, or just study hard in chemistry class, poisoning is even easier. Though to do all of this, you need to become a stalker and follow each family member for 1 week at minimum and learn their pass time and fav food, everyone has a pattern all you need to do is find it.
I don't know where you live, but different living conditions calls for different counter measures, like in the place where I live... I can easily poison a bunch of people if I want to , but arsoning will be a bit difficult, due to most houses comprising of bricks instead of wood.
The explosive countermeasure is the easiest, as you can easily find recipes from net and make a homemade device, but remember there is a strong smell during reaction and you can be found out, so you need a empty space during your concotions!!.
And you may be thinking why I was typing all this thing.... I will say... I don't know.. I was bored..... !!