Hopefully it will bring me out of my boredom of the game at the moment, but here's an interesting thought.
I was reading about a Gamefaqs post about how Rydia dies so easily vs Zeromus... and I didn't believe that was entirely true or fair. The prime reason for this is that many people make the mistake of equipping Rydia with the Heroine Robe/Minvera Bustier. This piece of equipment boosts pretty much the essential physical attributes (+15 STR, +15 AGI, +15 VIT/STA) but also cripples the others (-15 WIS/INT, -15 WILL/SPR). In essence, you are trading one issue for another. This armor is actually awesome for Rosa (even better than FF4A's misguided attempt to add the White Dress as her ultimate armor).
So, it got me thinking... with all the unfinished stuff about this game... was it possible that Rydia was supposed to become young again?
As we know, Rydia discusses about how time ages differently in the Land of Summoned Monsters (or Phantom Beasts or whatever you prefer to call them). This is obviously is compounded with the fact that she "never" learns Cure2/Cura when she comes back.
The two ultimate armors (in FF4, not the Advance port) that are provided for Rydia and Rosa in the Lunar Subterrane are the Heroine/Minerva Robe and White Robe. Given what we know about how things work, I would actually believe that the White Robe was intended for young Rydia and not so much Rosa. Rosa's stat progression will give her enough natural healing power (Cure4/Curaja isn't tremendously powerful IMO) that would totally favor the Heroine Robe. Rydia with her increased magic power with the White Robe would be much better at fighting Zeromus... even though the Sorceror/Light Robe provides greater benefits to her magic defense (+5 WIS/INT, +5 WILL/SPR vs the White Robe's +15 WILL/SPR).
Is it possible that the armors were tweaked poorly or was there some legitimate chance that Young Rydia was meant for Zeromus? Remember that there are very few equipment differences between Young and Older Rydia. Remember, Older Rydia gets to have a number of strength boosting equipment, but Younger Rydia has greater access to White Wizard equipment (Staffs and the White Robe).