An idea to improve PVP & sink server zeny
Add a wager system to PVP or @Duel so that players can make zeny off of eachother in PVP. You could also tax the zeny by 2 - 10% helping the servers economy. Not only will this give players incentive to PVP but it will also sink some of the servers zeny and not add any items/zeny to the server.