Day 1
Duchess has very low HP compared to other Nightfarers, so get level 2-3 before going anywhere. You should find a Fort or Encampment first. They have the easiest enemies and bosses to get you going till you reach level 5-6.
After that, you can either go towards a mine if you have a rare weapon you want to upgrade to epic, or you can go to a ruin to grind more runes. Keep in mind that going to a fort unlocks a map for you so that you can find some scarab beetles for talismans or hidden treasure for a good weapon.
There are some insanely strong talismans for Duchess. In this run, we mainly look for ones that improve either incantations or our lightning damage.
If we get lucky and find the key to an evergaol, get to it and do it since the rewards are often great. Do, however, not get baited into taking the runes all the time since the rewards are permanent and can be game-changing.
We aim to be level 8 by the end of day 1.
Day 2
On Day 2, we want to start looking for either a Field Boss, Castle, or Ruin. We can run towards a Crater if it spawns, but the really big one we want is Noklateo since it has a guaranteed legendary weapon drop from the boss inside, and the resurrection from the reward can be huge!
Keep finding consumables, especially anything that deals lightning damage, for this Nightlord.
Keep looking for weapon passives and try to get as high a level as possible for day 2!
If Noklateo didn’t spawn, you can also go to the central castle, which, especially if it has Crucible Knights, drops a ton of runes and good loot. The top and bottom bosses sometimes even drop legendary gear.
Day 3
We are fighting Fulghor for this guide, so here are some tips for his encounter.
Fulghor’s main weakness, as discussed, is lightning. It not only deals more damage to him but also allows you to interrupt his most dangerous attack. He spins around and gets ready to plunge his spear into the ground. INTERUPT THIS. If you don't interrupt it, a ton of spears will fall from the ground and do massive damage while Fulghor goes rampaging after you.
In phase 2, this attack becomes even more dangerous because he will debuff you, slowing you, meaning if you don't cancel his attack, he will also be able to run you down easily.
Phase 2 also has some dangerous AOE attacks where he grows a second arm and spasms it around. It's better to just run away and avoid this attack entirely instead of just trying to dodge it, cause getting hit is fairly easy and deals massive damage.