Obliterate, Then Iterate

Artifact is not what catches eye of Erus. No. You have demon armor scraps. Now, you might think to yourself, 'but Erus, demon armor scraps are junk', and you might be right. But Erus sees demon scraps and he does not see junk, he sees bronze. Bronze hidden in the junk. Listen closely, Erus will teach you how to use the Unraveling Sands. You put junk in sands, sands unravels it, and then you get bronze from the ashes. Try using the Unraveling Sands and then toss in the Legion armor scraps.