Any plan for improving the box drops for accounts that already have all the champions?
Both the box drops and the level ups unlock blue essence and the inability to sell all champions you already own...
The game is old, maybe think about optimizing and or retention. There is more than enough filler and valued assets to enable the grind among those who can't find use or reward from yet another already owned asset. Or add a new blue essence functionality, or just expect people to bleed off faster?
Easier to pre-emptively retain than try and re-entice those who get bored or find better returns on time invested.