Pokémon Mystery Dungeon: Explorers of Time Tips

Beating Dialga in 2 minutes
Have a half bag of Reviver Seeds (Brine Cave, common). Have quarter full of Sleep Seeds. Then Max Elixers filling up the last spots.

Treecko- Use Agility for more turns
Bulbsaur- Use Sleep Powder or Stun Spore
Others- Use items and Orans. You'll need them and also watch out for his 'Roar of Time'. It inflicts the whole but leaves Dialga giving a free hit.

Good Luck!