Small Spoilers ahead. A bit. It will be fleshed out more at some point. When your adventurers reach the end of each battleground they will ascend and free up the battleground and you collect an artifact item and add it to the global drop pool as well.
With the recent increase in boost costs, it is not possible to keep up using all the boosts with just quest rewards. And I am definitely not paying 20 USD for 25.000 gems. So I guess I'll keep playing until I run out of gems, and then leave the game. Well played.
Press esc -> options -> Turn off Music.