Crystalis/Amazones

Despite being accessible earlier, it is best to visit the Amazones once you have the Change spell since you really can't do much until you approach them disguised as a woman.

It is located in the southeast part of the Brynmaer area, with the river crossing being slightly south of east. Use the Ball of Water to freeze an ice bridge, and cross it.

In the Amazones village, there are two items to collect. Both require entering the eastern building by freezing the guard or changing into a woman.

In her house, you can speak with Aryllis and give her the Kirisa plant (found in Portoa Area, in the southeast cave). In return, you will receive the Bow of Moon.

In the basement of Aryllis' house, you can find the Blizzard Bracelet in a chest.

With those loose ends tied up, it's time to go to Mt. Hydra and locate the hidden rebel stronghold of Shyron.