This was actually just a test build, but it works very well and is fun.

Although this is a Nightblade, any class should be suitable for it, as the only class skill on the main line is Power Extraction, and that's really just because of the buff. Since every class has nice buffs that are enjoyable to use, the skill can be easily swapped out. If necessary, you can also create something nice with the Scribbling skill. :-)

At the moment, I am using Iceheart for head and shoulders. Of course, you can use something else according to your preferences. And yes, it is intentional that one part is medium and one part is heavy. This way, you benefit from Undaunted Mettle and can keep your main sets as light.

How it works:
Vampire level 4 is a must to get the most out of the vampire passives. The basic requirements are the Vampire Lord and Vampire's Kiss sets. Vampire Lord enhances the debuffs you have as an old vampire, but also the vampire skills, as they cost almost nothing. Vampire's Kiss ensures that we are constantly healed, as the mobs fall over in droves, triggering the 5-piece bonus permanently.

Solo content, like just running around in the world or exploring dungeons and vaults, is really fun. Just rush in or jump with Blood Mist, hypnotize everything, and mow them down... World bosses or the smaller bosses from dungeons and vaults can sometimes take a while, but they don't pose a danger. In case of emergency, you still have the Swarming Scion as an "oh-shit button."

Group content works too, but you might not be the strongest DPS, which is why I have the second bar as a healer; I personally feel more comfortable in groups that way. Since you are Vampire-4, you can also just run invisibly to the bosses and save the whole group a lot of fighting.

Have fun trying it out.