I want to suggest about changing the summoning pattern of world bosses. Like for example, Belphegor spawn in 20:20 server time , it takes hardly around 25-30 minutes due to lack of participants in this events since it is midnight here and also in other country and some of them are likely asleep . Last time when I'd played we have only 5-8 rangers with 2 dorams w/o RG in this event and I died a lot. LOL. It takes a lot of time and I'd get only 1 Evil Boss Fragment.
Well, I suggest if Werewolf should spawn at this times (20:20, 23:20 and 2:20[I don't know what time exactly] server time) since Werewolf is easy to kill unlike Belphegor (due to his servants) and at these time only few active players here.
And for Belphegor, it should spawn at (7:20, 11:20 and 16:20).