This is my Mesa build which focuses on Peacemaker and supreme survialbility with Shatter Shield.Also hold LMB to achieve fast shots in Peacemaker. Updated 2/20/2015
(You may use any dash you like, personally I switch between Corrosive Projection and Energy Siphon, depending on the situation.)
The very first Forma will go towards the aura slot because lets face it, Dash Polarity is the master race polarity for auras. The second and third Formas will be a D and V polarity so you can fit Transient Fortitude and Narrow Minded (dropped Narrow Minded for Primed Continuity)
For this build you will need energy efficiency so you can stay in Peacemaker as long as possible while also doing as much damage as possible and taking as little damage as possible. The first two mods are a max streamline and level 3 fleeting expertise. This allows for 70% energy efficiency (there is a 75% hard cap). I choose to do level 3 fleeting expertise so it does not cut into duration as much as a level 4 but you can choose which ever you like. Secondly we are going to have to maximize the power strength for Peacemaker and Shatter Shield. I choose not to include blind rage because the drain gets insane with max blind rage. Something along the lines of 14 energy a second (rather keep it at 2.5) even with max efficiency. Now a max Primed Continuity for Shatter Shield as it will last 20 seconds and deflect 95% of all incoming projectile damage. Using Shooting Gallery will also increase damage by about 50% to the person its on. As well as jamming guns near the player.
Now you have Primed Flow for a large energy pool to make Peacemaker last as long as possible. Then you want a max Vitality and Redirection because Shatter Shield will take whatever you have health and shields and multiply the effectiveness. With this build I was literally able to stand in front of a level 50 void heavy gunner and wait out the entire clip and only take 555 shield damage. Even then my sentinel just restored it instantly. It really helps while you're doing Peacemaker.
This build will result in you being able to do things like this.
Also hold LMB to achieve fast shots in Peacemaker
P.S. Peacemaker will only get faster and faster till it caps out at about the speed of an AkStiletto.