Power Scourge Axe & Focus / Greatsword GW2 Scourge WvW Builds
Scourge is the Necromancer that never has to commit. 
Mantle of Sand gives you shade and punishment skills; 
Manifest Sand Shade spends life force to place a shade on the ground, and after that every shade skill you press fires at you and at the shade. Damage, boon corruption and 
Barrier all land where you put them, not where you are standing.
The shade bar is a small kit with a job for each button. 
Nefarious Favor converts a condition on nearby allies into a boon. 
Sand Cascade shields them. 
Garish Pillar fears whatever is around the shade. 
Desert Shroud pulses damage and barrier at once.
Two builds live here and they want different fights. The power build is a backline body that shields the squad through 
Desert Empowerment and 
Abrasive Grit while corrupting boons for extra Barrier — a support that does damage, not the reverse. The condition build is a Trailblazer's attrition build that survives the front and waits for the enemy's cleanse to run dry.
If you want the melee Necromancer, see Reaper.
2 Scourge builds
Power Scourge Axe & Focus / Greatsword Condition Scourge Greatsword / Scepter & Torch Playing Scourge in WvW
The skill of Scourge is not the rotation, it is placement. A shade dropped where the enemy will be is worth several dropped where they were, and because every shade skill fires at both you and your shades, a badly placed shade halves everything you press for the next few seconds.
Both builds carry 
Trail of Anguish, which is worth knowing precisely: it breaks stuns, and it grants swiftness and 
Stability to allies who run through the sand behind you. That, plus 
Blood as Sand reducing your incoming damage whenever a shade is up, is most of the reason a Scourge survives a place a Reaper would not.
Where it struggles is a fight that gives it nothing to work with. The power build's Barrier runs through 
Feed from Corruption, so it needs enemy boons to strip; the condition build needs the enemy's cleanse to eventually fail. Against a disciplined group that arrives clean and cleanses on cue, both of them tick along contributing very little, and neither has the burst to change that.