Post any videos that you think will help attract new players.
Then use them in other forums to advertise the server (if the forum has an "other games" section or just in offtopic)
hint: duel tournaments and west glade pvp videos etc are BORING and UNINTERESTING. Also some "pro skill" showing off is again BORING.
I will start with these:
Dragonraja MV (GM version)
Ancient Dragon Raja Guide (v 0.69)
Dragon Raja war!!
I picked these videos because I think they would be good to watch for someone whos never seen Dragon Raja before.