@Angelfire
You should do them in order if only if you want to keep it strictly story wise. WoL's story is really hard, and it's only with some Dissidia experience under your belt that you can accomplish it properly, since there are some really tough boss fights in there.
@Simulacrum
Like Stefl said, the early battles in the tutorial are really really easy, just wait until you get to Warrior of Light story properly, or to the more harder story modes like Shade Impulse or Inward Chaos. Also when you get the Duel Colosseum, there will be fights that will take you easily over 5 minutes long ;)
I've posted a few videos a few pages ago (in the 2nd page if you're using the 50 posts per page) if you want to check out fights against Lvl 120 enemies.
Also, there's always Chaos xD
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