It is difficult to take on these cultists with a party of henchmen or less than level 20 players. They can overwhelm a party and their patrols are closely tied together. Luring a few will bring about at least six cultists, and Apprentices of Verata will raise Bone Fiends instead of their fallen and place great stress on the healers.
Samira is a challenging opponent if you venture into Kessex Peak with henchmen only. The differences in level (Samira, 24; Hench, 15) augment any damage greatly; the absence of a protection monk means all the damage always goes through; and the absence of a second monk (unless your character is one) means Alesia can be overwhelmed. On top of all that, Eyes of Verata will be raining their arrows. If possible, pull Samira far away from the mobs.
Samira is a character in Master of Chains by Guild Wars world designer Jess Lebow. Dhulnarim is the name of one of the cities in which Master of Chains takes place.