Head to the western area and youll find Duskveil in the shadow temple while Scorpionlord waits in the poison caves to the south. Duskveil is probably easier to handle first since his attacks are more predictable, and you can dodge most shadow balls by rolling sideways.

Get some practice with the basic dodge timing here since itll help later. Maybe interesting that breaking the shadow orbs in his arena gives you temporary immunity to dark damage. Once you get his pattern down just keep moving and attacking between his portal jumps, but watch out when he hits half health cause thats when the real fun starts with those tracking beams. Scorpionlord hits harder and has that poison field that builds up fast, so having the shadow resistance gear from Duskveil helps a ton.

Good to know that antidote herbs spawn in his arena corners, just dont get greedy trying to grab them when hes doing his tail sweep. The poison caves have better loot overall but dealing with both the boss and the environmental damage can be rough if youre not prepared.

Tip: breaking the glowing crystals temporarily clears poison in a small area which is super helpful during the fight.