if u want to get legendary survivor by doing the quest in gunnar's hold
press f11
action : use skill 8 ( the skill that u use when u are kd )
type a new key for this action
put in 9 & 0
now if u use 8,9,0 on your keyboard u should use skill number 8 , this makes u get up from kd three times faster , this makes u nearly impossible to kill , and safeguards your title
And if you get the thunderfists brass knuckles they are still considered the brawling weapon and will do full damage. and you can mod it how you want the best mods for it that ive seen is:
Furious(10% Chance double adrenaline)
Brawn over Brain Inscription (15% more damage/-5 Energy)
Dagger handle of shelter (+7 Armor vs. Physical).
since the energy is not based off your normal energy for your character the -5 from the inscription doesnt matter so you have the extra damage with no penalty. and same goes for health so the dagger handle is better than a fortitude mod so you can last longer without gettin KO. plus if you get and rock candies(Red and Blue are best) you are just a beast ive gone through a HM run and never got knockout for me to get back up.
and if assassin is your primary or secondary class u can do even more damage by placing all of your skill points in dagger mastery then in critical strikes
or if u are a warrior primary you can put as many points as possible in the strength attribute