Back again ..
In dungeons you want to wear Berserker trinkets and weapons (rifle usually). Good sigils are Force, Night, Fire, Accuracy, and Energy. For armor Assassin or Berserker work. Your rune can be either Scholar or Strength.
DnT put together a good video that breaks all of this down in greater detail: http://youtu.be/gipEa6IT8M0
Open world I like to veer more toward Celestial, but that’s a personal preference.
[EG] Ethereal Guardians
(edited by Phineas Poe.3018)
Assassins and Zerker are the best choice for the Engineer depending on your build/rune, etc.
Thaddeauz [xQCx]- QC GUILD