Weapon skins from Hell Eternal are available on Elite or Nightmare mode, depending on the weapon. They can also be purchased as a Weapon Mould in the item store. Outfit worn is the Infernal Finery from the Master Planner achievement.
Dao of Yen Lo Wang (Hadean Guard – Elite)
Bone Saw (Hadean Guard – Nightmare)
Shards of Muspelheim (Prime Maker – Nightmare)
Blood-Iron Kanabo (Eblis – Nightmare)
Xaphan’s Bellows (The Prime Maker – Nightmare)
Murmur (Eblis – Nightmare)
Kroxigan (Eblis – Elite)
Misery (Hadastean Guard – Nightmare)
Cauterizer (Eblis – Elite)
Creepy Doll (The Prime Maker – Nightmare)
Pandemonium (Hadean Guard – Nightmare)
The Green Heart (The Prime Maker – Elite)
Grimoire of Foul Gods (Eblis – Nightmare)
On Nightmare mode, there are four unique skins; the Creepy Doll Elementalism focus, Bone-Saw blade, Misery pistols and Grimoire of Foul Gods blood magic focus.
Thank you Shaun2406 for the screenshots.