Should you decide to do that, you'll likely end up looking for an easy way to level up your characters. Trust me, we all went there eventually; and it is fairly easy. And not really that exploitative either, for those of you who might worry about that.
So, what will you need?
- Ex-Death unlocked. (Which might be automatic, I forget. It's been a really long time.)
- The ability to set your Foe's level in a free battle to 100. (For max results.)
- A Manual Magic Pot summon. (You'll be able to tell it's Manual because it won't say Auto)
- (Optional) +Exp items (Chocobo feathers, etc.)
- (Optional) Bonus Day
So, watching that at first, you might just be wondering what the balls is going on. So I'll go ahead and explain it a little before getting into the finer details. As you might have noticed, at the start of this battle, Squall is level 1. This was on my Bonus day, and Squall had a Chocobo Feather on, with a Summon Used/Unused combo for a seamless 1.5x effect on his Experience. So, bonuses on top of bonuses is the key.
The overarching goal is to get Ex-Death to hit you with a Brave attack, not an HP attack. It will break you, and put his Brave all the way to 9999. All you have to do after that is avoid being hit even more than you were already. Then, the final goal is to use Magic Pot to get your Brave to 9999, attack him with an HP attack, and that's a One-Hit KO for anybody, even someone who has 99 levels on you.
So, here's what happened in the video. Starting at 0:10, I went poking at Ex-Death; not only because I was testing how apt he was to dodge my attacks, but because I was trying to force him to use his teleport. When he does that, he usually teleports more or less into you, which counts as a Brave attack. (Brave, btw, determines how much damage your HP attacks deal. As in, directly affects; the amount of Brave you have is the damage you deal.) When he'd do that, I'd hit Break status and bam, easy as that. This eventually does happen around 0:33. Afterward, you see I play a little keep away while also running in to grab the EX-Mode item. While not -necessary- to keep your foe away from these, allowing them to go into EX-Mode generally ends poorly for you.
Also vital to note is that I stayed away until my Brave refilled past Break. Always remember this. If you try to use Magic Pot while you're in Break status, it will miss, and you've lost it for that battle. Once you get to that point, Ex-Death has 9999 brave, and you're back from the brink, it's just a matter of picking your spot. Watch him while he moves and wait for a jump if possible; the worst that can happen is he teleports and Breaks you again. Then dash in, and for the optimal chances of not having your Magic Pot wasted, use it as you're executing your HP attack. Sometimes your foe will have summons that cut your Brave or the like and in those cases, you're in for a much longer fight. But they don't always activate instantaneously, so minimizing the window he can use it is key.
As you see, it goes off without a hitch. With one single attack, I gained nearly a million, (Million. With an M.) Exp, and that, coupled with the other few pick-and-prod attacks, one battle gained 65 levels for me. In just over a minute.
So there you are! Hopefully the video coupled with the explanation will help you if you decide to get Dissidia or already have it and are possibly playing it in anticipation of the prequel. (Yes it's a prequel. Why your levels carry over in that case is beyond me.)