The Guild Wars metagame changed radically when Nightfall was released. Tons of new skills and a couple of new characters make for a more demanding PvP gameplay. Since the dervish was introduced, players have tried and experimented all sorts of builds to make the most efficient scythe-wielding, transforming dude. Christian Bellisford, an established GW critic shares his views on the gods the dervish turned into. 

First off, Grenth, the god of death. Back when Night Fall was still new, you'd see Grenth dervishes in huge numbers at the arenas. As Bellisford says, this avatar easily took care of strong monk enchantments that made it easy to take a kill. Unfortunately, like most melee characters, they were easy to disable. A single Blinding Flash would make them see darkness and fail to hit.