I don't know if you still care, or figured it out already but I'll still answer. You must have beaten the first 7 Benevodons and have Duran (Dark) in your party. It is bought at the "Weapons Shop" in "Ancient Capital Pedda" for around 18 thousand Gold.

I don't know if your still interested, or figured it out already but I'll still say. Sorry, this may be long. It is Duran's Class 4 (Dark) ultimate weapon. Duran must be in Class 4 (Dark) before anything else. Dark Classes are the two right-hand paths when changing your Class, and Light Classes are the two left-hand paths. Whichever side you choose for Class 2, either Light or Dark, will tell you what Class 4 you wil be. After you are Class 4 (Dark) with Duran use Rainbow and Gold seeds in the Magic Pots. Now for the stupid part. All items from Seeds grown in the Magic Pot are based on RNG/Random Chance. I HATE this. For me the last piece of armor I needed was my Charlotte Class 4 (Light) armor. If you are trying to make a "All Equipment" file the Magic Pot will be your bigist headache. When first dealing with the Magic Pot you can't believe how easy it is to get the best weapons and armor for each Character and Class. After awhile you will start noticing that the Magic Pot gives you lots of stuff you already have and hardly anything new. This is that RNG/Random Chance crap thing I mentioned previously. There is no way around this,. The closer you get to having "One of everything" and "The better the weapon or armor" is the more you will notice this. By the time you are CLass 4 you probably only need a few things, including the "Good Stuff" for Class 4. This is when this "Random Chance" crap will be at it's peak. Again I needed my Charlotte's Class 4 (Light) armor for my final piece of armor and the Magic Pot would not give it to me. It kept giving me her Class 3 (Light) weapon and armor, my other party members Class 4 items, but not her Class 4 (Light) armor. This is when I got my Hurnting. FINALLY after 99 Rainbow Seeds and about 80 Gold seeds I got my Charlotte's Class 4 (Light) armor with a Gold Seed. Hope this helps.