Agh I hate boss battles.
1. Tediously long
2. Unpredictable-You'll never know when you die
3. The random order of the bosses, and eventually, Tabuu
4. Challenges like 'Defeat boss battles with all characters' 'clear boss battles on intense'
5. NO CONTINUES
The worst part, Boss Battle challenges are the ONLY challenges that you can't break open with the golden hammer. My hats off to you if you can beat it on intense.