Hello,
Well done! Mu Oldsquad is the best I've played in years, but I have a couple of concerns. These may be caused by my ignorance since I have only been playing for about two weeks, but I think they are legit remarks.
Medals, etc.
Problem #1: the items dropping from hearts and medals are way too good and abundant. For example, the first day I played on this server, I haphazardly found a Celestial Bow+11+Skill+Luck+4 just lying on the floor of Noria. If this item is worthless for someone, there is something wrong with the economy. I started as an Elf, and this immediately made every other bow I found myself useless. Only when things are scarce, they are valuable.
(Problem #2 [uncertain]: the fact that for some characters a Bronze set +11 (i.e. an energy mage maxing agi & ene) is already considered a good late game set, whereas for other characters it's worthless, is a bit too unbalanced I think. Every class should have some trouble to attain their best set.)
Solution:
Disable luck and options on items in medals. This increases the value of regular monster drops, and doesn't overpower the medal items. For example, you find Leather Gloves+7 from a medal, great! I look shiny now! But as you grind monsters, suddenly Leather Gloves+5+12+Luck drops. You don't look as shiny, but the item is way better than some cheap medal drop. This stimulates the economy
Decrease the max possible item level in medals to +8. This increases the value of luck on items. You got to do some work if you want to look super shiny.
Don't put super nice items in medals, like a Celestial Bow. This makes hunting or lurking for items way more fun, and stimulates the economy, again.
Items in shop
Problem: similar reasoning as above.
Solution: Remove the luck from the items. It's not luck if you can easily find or buy it.
Uniria, dinorant, angel, etc.
Problem Uniria: Useless for running speed because of the (nearly instant access) to small wings at level 80. Impale (such a beautiful skill) is useless as well
Solution: remove the small wings as an easy level 80 reward; there can be a much better event or box for such a cool item as wings.
Suggestions: Buff the impale skill; higher drop rate for Uniria and make them combinable to Dinorant without chaos. Or not, but then buff the Dinorant skill as well.
Problem Angel: rare, useful, but not really valuable.
Solution: should be in shop for a reasonable amount of zen. This make zen more useful, and Angels make the game look better.
Problem Imp: rare, valuable and useful, but hoarded. I have five of them now, but I'm not using them because they are too rare and they die so fast, just like Angels. Yet I don't want to sell them, nor would I want to pay jewels for them. I'm just waiting for the moment that never comes so I can use them when they die very slowly.
Solution: I'd put Imps in shop as well, for a price that could be described expensive, but not too expensive so no one wants to buy them. Doing this should increas the value of zen and the value of Imps. And now using Angels or Imps is a choice like choosing a stat build.
Drop rate
Problem: I think the drop rate of items is between OK and too high. It took me one day to collect a Great Dragon Set by just standing near parties who were killing monsters I'm still too weak for. Moreover, I got the Great Dragon Armor+1+8+Luck for free from someone who initially asked two chaos for it. I told him it wasn't worth that much, because it isn't, but it should be!
This problem is closely related to the overpowered items to be found in medals: because I easily obtained a random set of items +9, +10, +11, it was easy to survive near much too strong monsters.
Solution: decrease the drop rate, but increase the chance on luck or options. This stimulates active non-afk gameplay, because you have to be active to see your desirable items drop.
Jewels
I have never had such a hard time finding jewels, which is awesome and how it should be! But it's a double-edged sword. Because items from medals are so good and abundant, and jewels are so rare, I'm hoarding them and not using them. I'm not even going to try and make wings. I'll just buy the few items I want, and keep hoarding jewels until I can buy the item I want, without buying or leveling up any intermediate items from the market. (Nobody is buying my items as well.)
~Solution: Increase the likelihood of finding Bless by increasing the drop rate, or more recurring events specifically for Bless, and maybe a bit more Soul. The latter is the best option because it also stimulates active gameplay. [The events in this server are remarkably good; it's been years since I was motivated to participate in these events. They are challenging, fun, and necessary for jewels.]
Finding more Bless, and fewer items, will stimulate people in actually using it to level up items and buying intermediate items on the market.
It comes down to this:
early game it should be reasonably 'easy'/encouraged/fun to level up items to +7, +8, +9.
mid game it should be 'moderate'/challenging/fun to level up items to +10+11+12.
late game it should be 'difficult'/challenging/risky to level up items to +13+14+15.
Instead—what happens now I think—is that early and mid game is lost, and jewels are hoarded to save for the late game. This is boring. (Anyway, I've hosted a private server myself once, and the economy is incredibly difficult to get right, so this is just brainstorming.)
That being said, I think if finding Bless was 'moderate', Soul was 'hard', and Chaos the 'hardest', then it would make early, mid, and late game more fun while remaining a challenge.
I have more ideas and suggestions, but the somewhat broken economy is the most pressing for me right now. And it's getting late, so I'll end it here.