I did this on Brave.
The Ice Charm is on a dark energy island in Chilled Creek. As usual with dark energy areas, monsters will appear once you get near.
In order to get the Ice Charm, you have to defeat a trio of ice giants that shoot icicles at you. Having all 3 shoot at you at once is pretty much suicide (even dodge doesn't cut it), so I suggest you play it smart.
Before you reach the island they're on, you will have triggered 2 earth charm platforms. When you reach the island and see the giants appear, run back to the first of two platforms to dodge the icicle missiles. Then when the volley stops, jump to the second platform and shoot arrows at them until they shoot back at you. Jump back to the first platform until the coast is clear and repeat.
Equip yourself with the Fire Charm to do extra damage and you should get the 3 brutes down with little trouble.
Do note that once each ice giant is downed, it will spawn an ice wolf in its place. So make sure the coast is clear before proceeding.
Go under the now unlocked archway and touch the blue Ice Charm floating beyond the arch in a bowl.
Congratulations, you got the Ice Charm! Now equip the Ice Charm and shoot the blue-symboled areas on the water to the right. You'll summon ice platforms to act as stepping stones across to the other side. Onward!