Well, i'll just tell you this. I have done and collected pretty much everything with every character. The only thing i'm missing with Aqua is "second chance". I can't find the right melding combination for it(i love melding so, if you have nay questions, feel free to ask). I've beaten the mirage arena with all three of them, my advice: When you get to the "keepers of the arena" event. You'll have to fight Imprisoner III and IV. Use shotlock commands and two curagas with them, and you should be fine. As for Ven, you can use magnera+ faith, magnera +salvation and all of the rounds in the arena will fly by quickly.