Fortune means destiny or luck. At some point, people started using it to mean wealth, possibly because they were fortunate==lucky. Fate and destiny mostly have the same meaning. Fate is sometimes viewed as an active force (the Greeks had creatures called "The Fates" in their religion), choosing the path your life takes. It can also refer to how you die. Destiny is more often used to refer to a fixed point in your life, that is decided, sometimes by "fate" or some other mystical force. So if you said "He went to the store and met his fate there", that probably means he died. If you said "He went to the store and met his destiny there", that probably means he found his purpose in life. But, again, they basically mean the same thing, and you can almost always use them interchangeably. I can't quite understand your "torment" question. Torment means to cause pain or annoy. So I suppose Vikings can torment their enemies by raiding their villages. I admit I've never heard it that way, though.