Neathiron is one of the most important crafting materials in Diablo 4 Season 11, especially if you want to Masterwork or Sanctify your gear and reroll or push Greater Affixes on your best items. Unlike more common resources like Forgotten Souls or Obducite, Neathiron drops in smaller amounts and only from specific high-end activities, so you can't just grind anything at random. If your goal is...