I would suggest a couple of perks like the Burnished Weaponry along with the Feint Mastery (which provides a great deal of damage so he doesn't have to be on the passive during the combat) and maybe Crisis Management which lessen the suffered damage by 40% if your HP is less than half. Naturally there are more perks suitable for such a build apart from the mentioned ones so others may prove to be more useful to you.
I also suggest to put points on the Defense tree as well as points on the Warfare attributes. Using the Hit points skill tree can be a good option too!
Hope this will help. You can find other builds on our Steam forum or ask around on our Discord channel for more!