Spec for 100 Recovery and as much Discipline and Strength as you can. Swap harmonic mods for your Primary weapon's element. You'll want to use a Primary you're comfortable with and a Shotgun. Blink into the engagement, get a quick kill, then use Lightning Surge to push forward or Blink backward to get away. Use Phoenix Dive to descend if you're caught in the air, and don't forget about your Healing Grenade. If you're fighting high-skill players, swap Healing for Coldsnap to force the target(s) to reposition. Fragments are mostly down to preference; use what helps you hit triple 100 stats.
These build settings contain: