is this build actually viable, and has anyone actually seen one of these ever?

Made one last season. She was kinda weak though even with good gear. You will have to get good rare or crafted weapons until lvl 80+ since all spears before that sucks. Mine died to nm ardual around lvl 70, kinda dumb going up against him with a spear and a necro (and she already had it done ). Got Ardy to around 1/3 and then he decided to give me one of his famous dmg spikes. No lifebuffs make her pretty fragile.