I Hear You Like Rare Items?

No, I didn't make that picture, that's from Final Fantasy 12. But that's the point, it's a Zodiac Spear hunt.
I programmed in an item that is beyond Rare and Super Rare and even Ultra Rare to Stupid Rare. Let's explain:

• There are a series of urns in Hinata which are open for you to check for a rare spear item, provided you waited to open certain chests (I'll give you a strong hint, don't take anything from a house that is occupied)
• At the beginning of each play of the game (this is two playthroughs for the main game and Game Plus), two random numbers are rolled. One of these is 1 to 999 and is the main random number, the other is 0 through 20 for the number of urns that appear.
• So yeah, anywhere from zero to twenty urns are even open, and if the urns are not open you can't search. Since this is in the middle of the game, this means that you are effectively forced to start over.
• Assuming they are open, each uses a different set of nine numbers out of 999 (for example, one uses sequential numbers and another uses primes). There is some chance that none of the numbers give you a winning urn, in which case you also need to restart.
• Oh yes, and if they are not that number, you do get a minor item (such as a potion or antidote), but checking an urn closes a random amount of urns in addition to the one you checked.  So you might be able to check all urns if you are very lucky, but even then, you might get no urns that are anything other than rubbish consumables.
• I thought maybe this was a bit too awful. So I made seventh urn have a 1 in 4 chance of skipping the 999 random number and just giving you the item. But I'm not telling what position this urn is, as it's moved around a little.  And there's the fact that you could conceivably not have seven urns open and have to restart. 

Good Luck!