The DPS legendary ring effect should be used at the start of the fight with stacked CDs and a pre-pot, to quickly reduce Velhari's health and shorten Phase 1. Additional uses of this ring effect should be timed to increase DPS on the Ancient Harbinger and Ancient Sovereign adds that spawn early in Phase 2 and Phase 3.
The healing legendary ring effect should be used as a raid CD during every second Edict of Condemnation. The absorption effect that is applied at the end of the ring's effect will be useful for reducing raid damage between Edicts.
The tank legendary ring should be used to mitigate damage from the Infernal Tempest, Tainted Shadows, and Bulwark of the Tyrant abilities.