Mirror Prize Strategy
I'm sure there've been other topics regarding this subject, but I wasn't up to scanning through every topic, so I apologize if this subject has been exhausted already.
Today, I succeeded in attaining all 5 mirrors and the Nu Arcana in the Arena of the Ages - all 6 within a 24-hour period. I wanted to share my method, for any completionists who've found much frustration in filling out their item list because of these blasted mirrors. (I actually got the following method from someone else online, and it has worked great for me.)
As you very well may know, the mirrors and Arcana can usually only be attained after battling the "unattainable" monster in each tier, and even then very rarely (for example, the Ouroboros in Tier 1). So what I did is this: I sent my smidge out for training over and over again (while playing through the game of course), without battling my monster at all - so that it wouldn't evolve while training - until it's HP had risen from 1500 to about 2500. At this point, it was strong enough to defeat the Ouroboros pretty much every time. Then, I stopped training altogether and started battling in Tier 1, over and over again, saving after each battle with smidges, until the Ouroboros showed up.
I then fought it, beat it, and if I didn't get one of the 6 elusive items, I reset the game. This way, the Ouroboros would usually show up to battle again right away. I'd keep resetting until I got one of the 6 items. Then I'd battle smidges for 4 or 5 battles before fighting the Ouroboros again, and continue the process. The result? Well, although I had to endure getting one particular mirror to show up 8 TIMES before getting my last one, the end result was that I got all 6 items in one day, today.
It takes a lot of grinding, but it's not too bad in the long run - if you're a completionist like me, that is. And yes, you can indeed get all 6 items in Tier 1 (or any tier, for that matter). It just takes patience - make sure you have something to do while your monster is battling each battle (I spent the time playing Let's Catch and Wii Sports Baseball, both for Wii - games that required equally minimal attention...)