I think a ncie idea would be to add refine system that means you can go to npc and with special stones or gems bonus equips like +1 +2 +3 till highest. And at each level of uprage you have mroe chanche to fail. And PL can add special sucseess stones as very rare drp from bosses ingame. Higher dungeon bossees=Higher lvl sucssess stones. And it can be like +1=100% +2=90 or 80% and so on. But important is not to make this too easy. And the second idea for improving your power at lvl 50 is again gems or crystals dropped from bosses as very rare items. wWith these crystals you can add bonuses to equips like +3 str or more depending on quality of crystal. And something like chisels to digg holes in your equips where to put crystals. And last thing is that all these uprages have chanche of failure.