Goddamn Defence Battles. Three of them in about half an hour. Two of those, the first and last(which I can't win), were at the Arena Stage. Now, let me tell you about the Arena Stage battles. The Photon Converter, which you must protect or you'll die(presumably from the massive explosion, though oddly your companions are untouched by it), is right in the middle. Around it, are numerous cannons who, in addition to a high damage against the converter, also serve as Monster Generators, which each spawn endless waves(kill one wave, another appears) until you kill it(which kills all its associated monsters). The boss(which you must kill to win) is a really BIG cannon and is also a MG, and can survive a full salvo from your BIG f#$king cannon which has so far vaporized everything else I've shot with it(literally. They ceased to exist), taking about 60% of damage. The cannon takes about a minute to recharge, and with all the damage their cannons and monsters do, it takes about a minute for them to kill me. And I can't do enough damage with Cyrille to kill the boss in time. I did it the first time, and since then I'm keeping seperate saves between Defence Battles, but the second time, it's been too far away for me.
tl;dr: pwnt by cannons. And monsters.
Again, Shining Force EXA.