I did a zero experience game a long while back on ZSNES (using a small cheat at the beginning for the sole purpose of starting with a wallet in my inventory). If you manage to get a wallet through the arena though, it should basically be the same concept from there. Now, how did I beat Magus...? As I recall, I just ended up trying everything I could, and I somehow made it through eventually. I was able to do it with merely everything you can normally get at that point in the game; obviously I had no arena to grind in for capsules (however, I did have to give every single Magic Capsule I got to Robo to survive). Make good use of the two barriers, two Lapises, Robo, and the Silverenrg accessory (equipped on Robo). Also, stock up to at least 50 on Athenian Waters & Mid-potions. Keep trying and eventually you will get lucky. It can be done. Once you have Alya (and later, Magus), the game is a cakewalk, including Lavos, assuming you are a veteran CT player. In fact, it was so easy, I tried Lavos again with Crono-Marle-Robo (levels 1, 1, and 10, respectively). Also a success; just had to have all my best equipment on them, of course. One cannot beat Queen Zeal's final form without Magus or Ayla, though; I tried every equipment combination (although... elemental aegis was not available in the SNES version... also not sure if I tried Lifeline). Not sure how one would fare against the Dream Devourer. Hope this helps!