Get the rusty sword from Trodain. Earn a slime crown by fighting metal slimes or King slimes. One slime crown is inside the well on the hilltop hut. The final ingredient, Orihalcum, is difficult to get with an external cheat device. The easiest source is to accrue 83 medallions and trade them to Minnie for the item. Drop all three ingredients into the alchemy pot for the rare Liquid Metal Sword.