First thing is character balance. This server be like " You have to play BM if you want to have a stand in this server"
Second thing is Combo set, Full fire set and 800 master level.
You have to emagine how player feel boring when they reached the highest level of MU season 4 and they have to face with donated player with combo set and 800 master level. Donate is good but not for such thing like that.
Third thing is the is nothing to do in this server except Blood castle, and events from GMs and PvP on ring!
I love to play in this server because i like player here i have a lot of friends too, i play in this server tho talking and have fun with my friends
But for a time, they realize the problem of server and they leave.
I hope you will do some thing about it to make this server strong and popular and player will come