[Guidrage]

All taken from http://mysterytour.web.infoseek.co.jp/mt/eng/
I dont have Fenrir yet, if someone gets it please add it. Maybe a mod could sticky this for everyone to see.

Ramuh: Talk to Ripapa in Sailor`s Stay. Contents - It is said that if you offer a "Lightening otosha" over a big crystal in "Boyada Tree", a path will be opened. Try the challenge awaiting there. Recommended party of 6, over level 60. "Lightening Otosha" is a key item, and all party member
should have one (you`ll receive it when you are offered a quest).

Shiva: If "an icy tuning fork" can be smelled in the huge crystal in "FeiYin", a way will open. Challenge the trial for which it waits in it. Although it will fight with Shiva by BC, for entering into a circle, you have to have "an icy tuning fork."
Ifrit: Ring the tuning fork of fire upon the protocrystal in Ifrit's Cauldon. A path will open to the trial that await.

Garuda: Speak to Agado-Pugado and he will tell you about his encounter with the great Avatar of Wind. He says that the avatar had attacked his party when the Wind Protocrystal was resonated. He asks if you could help him calm this avatar's fury. If you accept, you will recieve the Tuning Fork of Wind.
The journey to the Protocrystal is a long road, and there are many tough enemies along the way. Even if you're level 75 you could run into trouble, so it's best to sneak and Invisible through the zones.
Through Altepa West, Through the Kuftal Tunnel, through Cape Teriggan, all the way into the Cloister of Gales. [Specifics are being researched]
When you reach the Cloister of Gales, you will find a giant green crystal before you, when your group is ready, examine the crystal and one by one your group will be teleported to the Battlefield.

Leviathan: Ring the tuning fork of water upon the protocrystal in the Den of Rancor. A path will open to the trial that awaits.

Titan: If "the tuning fork of the ground" can be smelled to huge crystal in "Quicksand Caves", a way will open. Challenge the trial for which it waits in it. Although it will fight with Titan by BC, for entering into a circle, you have to have "the tuning fork of the ground."