In Patch 10.2, you can unlock additional visual effects for certain Amirdrassil Tier Sets.
We assume this will work just like Dragonflight Season 2 Hero where you had to earn one of the following achievements to receive the item:
Mythic: Scalecommander Sarkareth
Dragonflight Keystone Hero: Season Two
For Season 3, you should earn Emerald Blossom Dreamstone upon completing one of the listed achievements:
Mythic: Fyrakk the Blazing – Defeat Fyrakk the Blazing in Amirdrassil on Mythic Difficulty.
Dragonflight Keystone Hero: Season Three Attain a Mythic Rating of at least 2500 during Dragonflight Season 3.
Elite: Dragonflight Season 3 – Earn the rank Elite during Dragonflight Season 3.
Once you obtain Emerald Blossom Dreamstone, the unlock will be account-wide.
Dragonflight Season 3 Master is also returning in Guardians of the Dream, awarding players with 1 Heroic Tier Set piece from Amirdrassil. You will find more details here.