Well server is dead. 3 people takes all heroes. Some classses overpowered like tanks, bladedancers etc. And weapons +16, tons of billions, mats etc. Noone will start here if you do not Wipe IT.
Make a harder server. Lower stats. Ofc DO NOT ADD TO GMSHOP more that S grade. You are destroying the game. Remove 3rd buffs from buffer. Let community make all the required chars.
If you need money to pay the server just ask for help to community. Or you can make Premium accounts, accesssories, agathions, hats etc and for those donators just give 1-2% more stats.
Remove THOSE BELTS and HATS (super speed pdef, mdef etc)
Fix the daily restarts.
Quests for farming items like festival adenas or silver-gold coins is super. Make a shop for those with various items. (eg. Soul Crystals 12-17 or color names, attribute stones and more )
PS. You have good files. Wipe it and you will see people again enjoying your hard work here.