The focus of this build is to cycle through action skills quickly, using the Infiltrator class mod to deplete your shield on the fly. This allows you to reap major bonuses from specific gear and kill skills at high upkeep rates.
Weapons: There aren't any real requirements for weapons with this build. I would recommend at least one gun that dumps a ton of projectiles (like a Linoge) just in case you need quick healing. There is some melee synergy if a [Brawler] Ward is used so high performing melee weapons could also work. See below.
Grenade Mod: Almost anything will work here I believe. A Chupa's Organ or a health only transfusion grenade would work great seeing as how your shields will (should) be down often. An It's Piss could also serve as a good enemy debuff as well. Keep in mind, as with most Zane builds, you will have little control over grenade usage.
Shield: A Ward * or The Band of Sirorak are the top shield choices. The Band of Sitorak may be difficult to use due to its low recharge delay. Other shields with depletion bonuses (like the Stop-Gap or Shooting Star) can work as well.
Class Mod: Infiltrator. The backbone of this build. Offers gun damage and movement speed bonuses the lower your shield. Breaks shield on action skill activation. You'll want one with cooldown bonuses and pluses to Violent Momentum and Supersonic Man.
* If going with a [Brawler] Ward, might as well go for a Face-Puncher and an artifact with melee bonuses as well.
Doubled Agent: The two priorities here are damage and health. Synchronicity and Donnybrook get maxed. After that, it's whatever. Supersonic man is a good choice with Violent Momentum. Don't spec into Borrowed Time as that decreases your action skill cycling.
Hitman: Same priorities as Doubled Agent, health and damage. Salvation is the only must max. After using an action skill, you'll be very vulnerable and this skill will be your highest source of health regen. As long as you spec into Seein Red, the path to get there doesn't matter. Below is the most general, good all around set.
Under Cover: Not taking anything from this tree. The first level offers nothing productive for this build and nothing in the next levels is worthwhile enough to waste five (5) skill points.
I have no idea if this is TVHM Mayhem 3 worthy but I'm having fun with it. I will eventually add hyperlinks for ease of use.
A slightly altered version of this build uses the SNTNL instead of the shield and puts points into action skill duration extension. The dopplebang augment is selected to speed action skill cycling. Action skill cooldown bonuses are heavily preferred for the artifact and class mods here. Getting Digi-Clone cooldown below 15 second allows continuous kill skill bonus upkeep.