The Hades Cup
After the initial scene talk to Pain to enter the Hades Cup. The battles here are scripted and Hercules fights alongside the party. After you clear two rounds Auron shows up to trigger a scene. Chase him to the Cave of the Dead for a scene then talk to him at the Underworld Entrance. Time to make the trek to Hades Chamber, all the way at the far end of the Cave of the Dead.
Monster - Crescendo
Crescendos are inspired from the Alice and Wonderland horn-duck. They use a Trumpet Strike to melee Sora at close range and can use Trumpet Summon to call in reinforcements. In addition, Crescendos can use Healing Trumpet to restore HP to other Heartless. Use the Reaction Command "Heal Stomp" when the Crescendo is going to blow its trumpet to be healed instead!
In the Cave of the Dead: Passage you can leap from the high point in the middle to reach Dawn #25 . In Hades’ Chamber, Sora will collect Auron’s Statue but then a bunch of Dusks appear and have to defeat them all. Save at the Underworld Entrance and enter the Hades’ Cup once more.
BOSS - Hades
The battle against Hades starts with you being unable to harm him. A quick scene takes place and Hercules enters the fray. You’ll a need to use "Aura Sphere" to take Hades out of his red form. In his blue form, Hades is ripe for attack so let him have it! He will use Ring of Fire where he spins in a circle and creates a pillar. It is hard to avoid at close range so just be on your toes – this move is indicated by Hades shouting, "That’s it!"
If you are having trouble avoiding attacks you can always stand by Hercules and use the Reaction Command to defend. In fact, if you stay by him the entire time, you can keep up the Guard Sphere and just use Aura Sphere over and over to deal safe reliable damage to Hades.
Rewards : HP +5 (Sora), Magnet Splash (Sora), Accessory Slot (Donald), HP +5 (Goofy), HP +15 (Auron)
After the battle you receive the Guardian Soul Keyblade . Return to the Coliseum and head to the Underworld Caverns: Entrance. Leap across to the far end and then out to Dawn #34. In The Lost Road you can leap up and claim two more pieces, Dawn #40 and Dawn #46 . You unlock the Titan Cup now so you can visit Panic once more.