PvP Arena event starts everyday at 19:50 and ending 20:00 server time.
You can teleport to PvP Arena via M teleport menu (700+ level needed).

Event consists of 3 parts:
a) 10 Mini Bosses are spawned every minute from 19:50 to 20:00
Reward from Mini Boss: 1x Jewel of Creation / 3x Jewel of Soul / 3x Elemental Rune
b) Big Boss will be spawned at 19:55 and stays until 20:00
Reward from Big Boss: the same like drop from God of Darkness (reward will be updated later)
c) Killing other players from 19:50 to 20:00
Kill other players and gain points in King of Duel rankings https://empiremu.net/x500/rankings/arenapvptopkillers/
(PvP is free)