Chests and Key Fragments
Both old and new system for dropping key fragments are bad, the old one was farmed and the new one is way too random and doesn't feel like an achievement or satisfying.
I'm sure most of you heard of battlerite on steam and how it's hard to stop playing that game since there's a lot of things to do; there's achievements, character's levels... and this way it's addictive and always fun, not only the gameplay is fun but also rewarding. And I think that league can be like that game, I think there should be missions for key fragments and even for chests, add this to the first win of the day and the events/clash game mode and it'll be great.
As for the new missions, they can keep it with getting certain objectives in games and getting S rank so it encourages players to play better, you get the usual weekly chest mission and probably weekly key fragment missions; they can make it so it's an easy mission for one key fragment and once you finish it there'll be an extra key fragment added to this series of missions and it'll be a harder mission and it ends with a third key fragment with a pretty hard one that you need to finish before the week ends or else you get the key fragments that you worked for.
So you end up with a chest and a key if you were successful with more satisfaction compared to this system where it's all random (quick note, honor comes here where you're allowed to get 2 key fragments missions a week for level 2 and for level 3 and above you get 3 key fragments missions; below these ones you only get one so it punishes unhonorable players)