Suggestion: A cool thing to do would be giving blues and yellows' Kings the option to declare a Kingdom Siege War. The more players in the Siege War arena, the better, and every char of the entire server could join and have impact on the war. If we got a siege war with 20 players each side would be very balanced and strategy would play a role.
The winner kingdom would get some bonus for 2 hours, for example 30% exp, double the gold rate, 5% damage, or activate an alternative drop with low chance for all the kingdom's players that wouldn't mess up the server's economy such as a Cursed Ring (the one that makes you able to transform other players into monsters as a prank). The bonuses wouldn't be cumulative so you couldn't spam Kingdom Sieges for 20% + 20% + 20% exp, so if you did a second Siege War before the 2 hours bonus ended it would either give a different bonus or no bonus at all.
In order to ensure the war is not exploited, you can do 2 things:
1) the war has to have a minimum amount of players joining in order for the reward bonus for winning to be given (ex: 40 total players).
2) 1 person per IP restriction, it was done in dungeons so it can be done to access this war, people that want to fight and buff at the same time won't be able to do, which is fair since buffing it's a huge help and part of the advantage of playing a mage; besides it won't be a problem because if 20 people join each side, for example, i'm sure there will be a dragon mage there.
Only problem I see is that both Kings have to be online, but for example the Kings we have now are quite active so it won't be problem most occasions.
I'd also like to suggest to do a slight change at the Siege War mechanics regarding the start time. Put a 3 minute timer after the war request is accepted in order to avoid some players rushing the metins at the start, even though that's kinda part of the war...The reason behind this is that some players which would be in a middle of something or would have to remove the equipment to the inventory or would have to access the warehouse or would have to quickly buy Siege equipment at the Hong-Hae Npc would have a margin to arrive a bit later and we could start the war with most people ready. During the 3 minutes there would be a physical barrier at the start of the map which wouldn't allow them to move further into the center of the map. (I hope this is feasible)
I think this would stimulate the server's PvP and would be a cool feature to have.
I'd appreciate feedback and a reply, thanks !