Predecessor Builds > Zarus > Updated Zarus

Augmentation and Earthshaker are must haves. The rest are whatever you'd like. I enjoy nuclear rounds and equinox because of the extra damage from their passives along with earthshaker making for some really nice damage. After that is situational defense items. Fist of razuul is pretty nice because of the healing. Instead of citadel you could also go dawnstar. Reducing enemy damage can be pretty nice