Chelsith Reborn is broken up into 3 levels of difficulty. All of these difficulty levels fall within the current "tier" of the zone, but provide a variety of playstyle within the zone.
Safe: No aggro mobs
Easy: Aggro mobs, but lower stats and more spread out for easy pulls. Meant to be soloable
Medium: Aggro mobs, moderate stats, and some more multi-unit pulls. Meant to be done with very careful soloing or small groups
Hard: Aggro mobs, higher stats, mostly multi-unit pulls. Meant to be done in a group.