Col. Vessery + HLC + PTL + Twin ion engine

Kath + Mangler cannon + cluster mines + calculation + Mara Jade + EU.

Was going for a crit. stress build but any help on this would be great.

Reb Cap > Mara on Firesprays

I think you would be best to go with Rexler Brath instead of Vessery and here is why.

Vessery needs a teamates that will TL for him. The way Kath is build, you will either take a Focus (Calculation) or Boost, no time to take the TL. If you go with Brath, both ship will fonction independantly from each other, and he even fits better in your Crit heavy theme.

To free the 2 points needed, I would get rid of the Cluster Mines on Kath, and with the 2 points left, I would probably upgrade Calculation for Predator. You already have the Mangler Cannon for the crit, and it will help you offensively when you will decide to boost. In a 2 ship build, you can't be allowed to miss often.

Agreed that Rebel Captive is better than Mara Jade, especially since your Kath will likely make it to late-game where RebCap becomes even more powerful.

I think Vess pairs fine with Kath who might be vulnerable on the turn she TLs but is otherwise not reliant on that TL at all. Rex with Twin Ion, HLC, and PTL is an absolute monster though.

And Kath could benefit more from Predator, Lone Wolf or VI instead of Calculation. Your Mangler is already generating your crits/stress, so Calculation will only give you another crit but at the cost of not being able to use that focus for defense or multiple red eyes. In a two-ship list, you need as much damage as you can get from both ships. Calculation isn't a bad upgrade, but LW or Predator will enhance your damage output.

You' ve got fairly low PS and nothing that is particularly tanky. I think you'll find more bad matchups with this list than good ones.