Made it to Silver I today and this is my max achievable league given my cards unless I rent or buy 30,000 DEC worth which I won't do at the moment unless there's a protection mechanism to cover the season ending rewards.
I got the Neutral Quest today which is pretty straightforward. You just have to remember not to use the Furious Chicken and Slime.
After 3 wins, it is time to collect the loot. Nothing much to sing about, unfortunately.
I wonder if the game assigns loot to players based on their ID hashed with another variable or if it is completely random. Just my experience is that I have hot streaks where I keep getting good rewards and periods where the rewards are terrible. Like now.