Wilygrayfox

I'm a long time gamer but new to POE. I'm following some of NerdCommando's guides. I planned to build Eder based on his Lady of Pain build. Weird thing is Disciplined Barrage is not one of his possible selections. I can't find anything related to this online. I may buy POE2 based on my experience with the first, but I just would like to know why it's not a selectable ability.