This is a one time visit, so make sure to farm all bestiary:

• Leshy
• Ironback
• Armadillo
• Black Lizard
• White Mousse
• Medusa
• Mystery Egg 
• Skuldier
• Blood Bat 
• Steel Golem
• Coeurl
• Sorcerer
• Mad Ogre
• Lamia Matriarch
• Mythril Golem
• Storm Anima
• Lamia
• Ghost Knight
• Balloon

Once you reach #6, there are bosses waiting for you.

Bosses: King and Queen Eblan
Well, it's very sinful to kill your own parents. So, just defend and heal, and everything will be fine.

Boss: Rubycante
Strategy: Edge use Steal on him when he open his cloak, trust me you don't want to see Inferno.

Item checklist:

• Unicorn Horn
• Silver Hourglass
• Ogrekiller
• Lilith's Kiss
• Ashura
• 10000 gil
• Hi-Potion