A game on my frustration list? Bowser's Inside Story, strangely.
I don't know how, but every time I retry the fight I'm stuck on (), I keep losing! Maybe I should just level up a bit...
The Mario and Luigi series is awesome because every enemy attack in the game can be nulled. If you practice dodging the boss's attacks, you should be able to pick it up.
Meanwhile, boss battles are basically the entire purpose behind those special attacks. Spam You Who Cannons, basically.