Since we are heading into another new (pre) season very soon, and I know that you fine devs are chomping at the bit to launch, there are a few things that I hope you will keep in mind as we progress toward that:
(When it comes to soulstones or any other character progression stuff:)
Players who have access to very powerful things, will not be segregated amongst themselves with these very powerful things. They will find any way to grief/rage bait/whatever your newer player base while practically untouchable. The newer players will stop playing - it's happened countless times in countless online games. It's very sad that this is the case, but I think this is the only reasonable way to approach any new features like soulstones.
The best bet, IMHO, is to keep character progression systems as close to the themes of the classes as possible. I would make them class-specific myself. Otherwise, people will pinpoint the strongest meta and that is what absolutely everybody will run. (If you can just freeze people and burn their hp bar with complete immunity, why the hell wouldn't you do it?)
Perhaps most importantly, please do some optimization of your game client and your servers & network! I and many others continue to have crazy sudden disconnects or massive lag spikes during games.
I want to keep loving this game - but there are many things that keep me from logging in like I once did.