i want to make a vitality caster build but i’m not sure which masteries work best. i assume the occultist is a good one, but should the second be a necromancer, a shaman, or something else?
For Vitality caster your best build will be with Dark one set. It supports three classes and all the combinations in-between them. They are Necronancer, Occultist and Shaman.
Have a look at the Build Compendium to find some inspiration/direction for vitality caster builds. You can also find the builds Nery mentioned there.