It's perhaps part of Final Fantasy Legend's charm, but there were so many janky things about this game I don't know where to begin. Frustrating: I don't know when my mutants increase their stats or which stat is increased until I check. I don't know what abilities they gain or lose until I check, and there seems to be no rhyme or reason to what's dropped. Amusing: My mutant went from having 10 uses of Mirror, 3 uses of Power and 23 uses of ESP one battle to having 40, 1, and 66 respectively. Also, she somehow got to 99 Mana before I beat Sei-Ryu. 
 
Maybe I'm just ass-crazy, but this jankiness is one reason why I still play it today. Well, that and I know what to expect already, I guess. If I had to play a janky retail game in this day and age I don't think I'd last past hour 2.

I have really fond memories of this game, but yea, it was pretty janky.  The mutant transformation thing was really lame, but that's probably why they had the quick reset function (a,b,select,start). 
 
I also remember abusing quick reset to ensure I got the maximum amount of upgrade when using the permanent upgrade consumables like HP200.  They would increase your HP permanently by a random amount (between 5 and 20)... they were pretty costly too, so it's not like you wanted to only get 5 HP increase out of them.