Why would a dervish need a second profession anyway? they got already everything they need: Damage/Healing/Protection!
I`ve been thinking of making a pure dervish build, and ive made one (havent tested it yet, havent made a dervish even yet cause i couldnt think of a nice second proff)
8.Avatar of Melandru
If im correct, the skills that end an enchantment end the last one you cast (not sure correct me if im wrong ill adjust the build on it then)
First cast Faithfull, then Watchfull. (:O nice life safers ^^ with high enough mysticism they give u the energy back and u recast them :D)
Cast Conviction on yourself (Extra Armor :D and good for Mystic Sweep ;))
Cast Mystic Regen on yourself when needed and cast Vital Boon always with it, Explain: Conviction ends an enchant when it ends, if u have Vital Boon on yourself it ends and u get the health! this 2 skills are the main-heal of the build (if it goes wrong u got the 2 interventions! :D)
Melandru`s When needed (very nice cuz u dont have probs. with conditions and the life bonus is hughe!), if u got Melandru`s use Wearying Scythe else not!
Mystic Sweep -> see all the enchants!! nice extra damage :D
Hit for High(est) Mysticism (preferably 15 so u get 5 energy back when an enchantment ends, and all your enchants are 5energy (except watchfull intervention) so u can recast them if they end right away), rest of it put into Earth and Scythe Mastery
anyhow, ill mainly use this for PvP i guess, in PvE its ok but u cant use melandru`s that often in it (or u need to kill a boss mob)