This build is for mobbing and solo play. It focuses on Duct Tape Mod, Drone Delivery, Fractal Frags, and Pocket Full of Grenades to put as many grenades in play as possible. Basically you're putting a grenade in play every 8-10 seconds and never run out. The shield you use isn't all that important, but I use a Resonnant Back Ham. This build is somewhat tanky because of Rise to the Occasion and Ready For Action, but still cranks out high AoE damage.
Weapons that go well with this build should have a small clip size (to trigger Duct Tape Mod) and preferably do AoE damage. ( Devastator, Shocking 9-Volt, Speedloadin' Hellwalker, Brainstormer, Flakker, Protuberance, Conference Call, Fearmonger, most Torgue weapons) The Grenade Mod I use is the Recurring Hex.
Keeping with the Mobbing theme, the Techspert class mod is what I'm using. This build can be shotgun and Torgue heavy, so look for bonuses on those.
This isn't super important, but the Victory Rush works well and stays with the KillSkill theme.
Always keep your Action Skills active, and stay moving. When activating your clone, swap with him immediately to get the +20% Gun Damage from Double Barrel. If you need more Boss killing power, have a Lyuda in hand when you activate your clone, and swap the Hex grenades out for Porcelain Pipe Bomb or Fastball.