just want to be 100% about it before i decide whether or not i'm participating.
i heard it was a pot burning event and there are 5 towers (30, 60, 100, 120*, 150** floor towers)
* 120 floor towers opens up at random for 15minutes or requires 3 dark stones to unlock. completing this tower randomly awards you 6* alto or a 5*
** 150 floor tower opens up at random for 15minutes or requires 7 dark stones to unlock. completing this tower awards you a 6* monster
light stones increase bt gained for 15minutes. you can get light and dark stones from finishing every few floors of the tower (10? i'm not sure on this number)
it is actually a training/tower event. you spend training points to walk and you fight monsters quest style? and at the end of every ?10? (again, not sure on this number) you fight a boss.
the heroes return series pack units only increase your damage dealt to the bosses/quest mobs.
you get artifacts (for beating bosses? not sure on this too). there are 3 sets of artifacts.
is this all correct? i think i read some of this somewhere and pieced it together using google translate on the jp wiki.