Looking for a 'reaper' build?
Sounds like you’re talking about the Viper Horror condi build:
http://metabattle.com/wiki/Build:Reaper_-_Viper_Horror
However, for this build you will need a lot of gold, crafter characters to make the gear (Viper gear needs to be crafted since it is bind to account, or obtained through raiding) and the trinkets needed are only obtainable through raiding (Vipers) or are gated behind completing somewhat annoying and buggy achievements in the LW Season 2 story (Sinister trinkets) or HoT story (Viper amulet). I have been working on getting some of this gear outside of raiding and to be honest I am about ready to just give in and get the less desirable Rampager trinkets instead.
Or you can just go with a power reaper build (minion build or shout/well build) and breeze through all open world/dungeon and low-mid level fractal content.
This is the closest I can get to my build with the builder. I use trailblazer’s everything, with fire and condi duration consumables. Maintains around 9-10 stacks of burning, around 7000 dps, and is tankier than a nomad guardian. It’s not meta, but I’d say it’s just as effective and a hell of a lot more fun than sticking to what everyone says you should use.