Latest Astral Realm update bring us 100 vs. 100 PvP Arena called Golden Desert. Still no news about GvG.
astral realm 100 vs 100 arena
You can join arena from 20:00 until 20:30, battle last for 30 minutes. If more than 200 players join game I think game create second arena.
astral realm 100 vs 100 golden desert
Golden Desert -
5 Towers.
2 Teams (Blue and Red, you can't chose your team).

To win you must conquer towers and keep killing enemy players.
astral realm dragon
Dragon -
Similar to dragon in MOBA games and Echo of Soul. If your team kill him you got points and buff.
astral realm furniture
Battle rewards -
Star Stones, furniture, mount and some more rewards.
astral realm 100 vs 100 mount
Right now you can play in Astral Realm on Japanese and HK servers.