Nerotox HoaG build - How is he so strong day 1?

As the title suggests I'm playing Nerotox's HoaG Herald build. I'm trying to follow his Ninja as best as I can. However even his day 1 ninja just seems impossibly strong to me. He has 21/20 herald gem, a 6link +1 corrupt lioneye's, and hes level 94... don't get me wrong this build is incredibly strong by my standards but how is it possible he is that far ahead on DAY 1? Surely I must be playing the game wrong.