WvW Phantasmal Jerk
try this shatter build if you want to live a little dangerously and blow everything up.
conversely here is the same website with a blank template if you want to theory craft your own build. http://gw2buildcraft.com/calculator/mesmer/?4.0|0.0.0.0.0.0|0.0.0.0.0.0|0.0.0.0.0.0.0.0.0.0.0.0|0.0.0.0.0.0.0.0.0.0.0.0|0.0.0.0.0|0.0|0.0.0.0.0|e
If you’re looking for dungeons for Berserker stats go for CoE, CoF and Arah.
Phantasms can run full berserk, although I sometimes switch to my valkyrie armor set for a little more beef and a different runeset, but the difference between the two is slightly negligible (2k hp vs 10% crit chance).
For runes, if you want the cheap route, go for Ruby Orbs. You can switch to something like Runes of the Air or Centaur for more mobility, Scholar if you’re extremely competent, Melandru for condition defense, and a few other sets which are all your preference.
Sigils, you’re going to want Energy (if you can afford it) and probably a Bloodlust or Precision stacking sigil. You can also run some Night on secondary weapon sets (preferably with Ghastly [Ascalonion Catacombs] skin so they glow at night so you see if the sigils are on or off). You can also run Battle, Might, Accuracy, Force, Air, Fire. There are a few things I’m missing.