Hi, i not sure if this is okay to discuss here, since exp ball is important for leveling and valuable in medal, keeping it in store become troublesome as it currently designed as not to stack and it consume a lot of space. I suggest a new NPC required to convert exp ball into chest like L gem chest, G gem chest, say 10 exp ball for a chest and it can be stack for 15 chest each like other. Knowing it will have same bug issue but it is still better than create a lot of dummy account just to keep the exp ball.
If a new npc to convert 10 of 50k exp ball into one 500k exp ball and 10 of 500k exp ball into one 5m ball is another better idea?
Thanks for your time to read this.