My playstyle usually involves avoiding damage altogether and that can work in this game theres a few tools to completely avoid it skillfully rather than tanking it with your hp and resistance numbers.Well even with fighters guild members, you should mostly fear them if its 2 of them vs 1.
As a nightblade having invisibility, teleporting strikes, there is little need for vampirism or anything else if you plan on ganking only, also vampires get a huge damage spike from anything with fire in it.... so a fighters guild DK will probably tear you a new one.