Arcane Adventures had several known Sea Curse-imbued weapons, such as the Sword of Morock’s Fire and Arsen’s unnamed sword. But Arcane Odyssey, despite having far more curse users, did not have any known curse weapons to my knowledge. Until now, with the remodeled corpses at Blasted Rock!
The sword that Zaix is impaled with has a green blade, the color of Slash. And we know his killer, Avery Walker, had the Slash Curse and was a skilled swordsman. It must be an arcanium sword, since it remained infused with Slash Magic long after receiving zero contact with its wielder. This is something we only see with weapons that have some degree of arcanium in them; the Sunken Sword, Sunken Staff, Triasta of Bronze, etc.
As for why we don’t just take this overpowered curse weapon and use it ourselves… I assume it would be extremely dangerous to wield due to its unique properties. We’d probably dice ourselves up. Avery was likely a master of the blade already before he got his curse and started using it with his weapon.
Oh hey, Kessler Boreas was stated to be skilled with a spear, so I bet he had a Darkness-imbued arcanium spear too. It’s not a confirmed curse weapon but we can be pretty confident.
Not gonna lie I originally thought that was just an oxidified bronze blade, but this actually makes more sense since oxidified bronze don’t even look like that and I doubt that Avery Walker would use a bronze blade as well