Trial for the Brave
From Battle of the Immortals Wiki
Note: in the game the name of this event is generally abbreviated as "TOB", although the name is Trial for the Brave.
The difficulty like most events is determined by the average player level, therefore it is important with Trial for the Brave to squad with players your own level or it will be extremely difficult to complete.
Trial for the Brave has 2 modes - easy and normal, in both cases you want a full squad of players.
The challenge is to wipe out 15 waves of mobs in the small amount of time you have for this quest and then kill the boss at the end.
At certain intervals a totem pole/purple tower will spawn and you have 50 seconds in which to kill it. If you do not kill the totem/tower super hard mobs will spawn that will slow you down and make it virtually impossible to complete in time.