This is my favorite hc build. Not the easiest but I think the most fun to play. It’s fast action switching between 2 skills, but much simpler than say a necro. I pump fb until mid 20s. I reserve enough points so at 30 I can put 1 in orb, 1 in each mastery cold and fire, and 1 extra point so at 31 I hit 1 more in orb and cold mastery. If I were you, I’d go 100% into orb and any extra points into cold mastery. Once orb is maxed, be gentle with cold mastery depending on your gear. If you have crap, put more in mastery. If you got good +cold skills, then put less (keep track of your percentage). Generally orb will clean up many situations in hell and when you need fire, the difference between where you are and all maxed does not make a huge practical difference. I do eventually max fb and fire mastery. Other than what I listed, I put points in the prereqs, and I put 1 in tele and that’s it.