its based on luck. you dont need any good gear for it, just for the way to reach this point.
you can attempt any time from level 71 onwards, gain guild points and unlock new characters if pass.
Guild Points Explained
Fail -> No Character Unlocked -> 1 Guild Point
Feeder Class -> Samurai - 2 Guild Points for a Pass
Samurai -> Paladin - 5 Guild Points for a Pass
Paladin -> Monk - 6 Guild Points for a Pass
Monk -> Ninja - 10 Guild Points for a Pass
Ninja -> Warlock - xx Guild Points for a Pass - unknown at this time
Warlock -> Headhunter -xx Guild Points for a Pass - unknown at this time
Headhunter -> Alchemist - xx Guild Points for a Pass - unknown at this time
Alchemist -> Reset Season - 100 Guild Points
Note* In Hardcore The Guild Points Are Doubled.
no one will tell you what it
exactly is, get to level 71 and find out yourself.
it would destroy the thrill if you know what happens before the 1. try, so dont spoil it for yourself, it will not make you happy