Nube build under lev 80

Currently at lev 51 and I'm getting killed quit a bit at act 5 part 2. I'm trying to figure out how these complicated builds work. I tried the Tornado Build and I'm only shooting one single shot that splits into 2 or 3 arrows at impact. Videos of other players show 5 or more shots at a time doing tons of damage. I got all the gems they said to get and nothing....One single arrow at a time. What am I doing wrong???