Use a decent shotgun w around 600 ammo and a cactus broth tgen you can do the boss solo

Take a few good pumps and cactussoups and shoot at his arms! Dont get to near to the nameless and Reapers!

Well easy on foot with 200+ damage shotty around 600 ammo and a cactus broth enabled and just shoot it done

Well i recomdmend getting artifacts for it on other maps and then transfer it to aber it will be much easyer like that also u can start bossfight with any of drops there so u have not to go to terminal and yea dont forget ur cactus broth