During the event, the instance Epoch Crack will be opened.  The NPC Original Zen Master in Snow City / Azure City can help teleport you into the instance.  If you can perish all monsters there in 30 minutes, you will be able to face the BOSS.  But if you exceed the time, you won't meet BOSS even though all monsters are perished.  Defeating monsters and the BOSS there earns you tons of experience.
 

Equipment, Experience