DNA Dark is a highly customizable, free Substratum theme that probably contains most of what your device needs. Not only does it sport a fancy dashboard (through which you can report bugs), but it also includes custom boot animations, fonts, and more. The theme religiously follows Google's Material Design guidelines and has two versions of the theme packed into one application. These two versions are the "regular" DNA Dark iteration and the "Infected" DNA Dark iteration respectively.

The status bar looks extremely professional. It has a high dependency on the type of icons you choose natively. I currently have the Circle battery icon applied, and it looks as good as the Solid battery icon does in my opinion. I would recommend you try out the Portrait battery icon.

Mike (the developer) likes to keep things professional with his theme, which happens to be the reason for a small divider between individual notifications. There are a lot of people in love with the divider and @customworx, happens to be one of them:

t is visually easier for me to interact with the separate notifications because of the dividers. Mike has done some real work with the dividers.

Moving towards the Quick Settings Panel, you'll notice that some icons have not been themed. However, the flat look of the panel and the brightness icon redeem this aspect. The brightness slider is equally as visually appealing as the icon is. Almost exactly like the Quick Settings Panel, the Settings menu has a flat layout. However, you do have an option to toggle sections on.

The Navigation Bar overlay included in the theme is quite interesting. There are 5 unique styles of navbar icons included, namely, the Solid, SolidAccent, SolidOutline, Transparent and TransparentAccent styles. In addition to all of the options and styles mentioned above, Mike decided to include custom animations as well.

If you're interested in this theme, check it out on the Google Play Store in order to download it or circle follow Mike (xdnax) on Google+.