I never really understand the benefits of upgrading the level of you Steem monster cards till yesterday when I had to upgrade my cards with my Steem. Someone once said " since the price of Steem is down, the best way is to utilize it in things that will generate more income for you instead of consuming them" and I also noticed that after the last season, my rank a barely increase. Anytime I reach 659, they will beat me with baton back down (I will start losing battles).
Since I have some Steem, I decided to upgrade my cards, started with the life Steem monster card which I do use most time and currently most are in level 3. Surprisingly for me, I started wining battles, will soon be in sliver stage II and my Dec too is really increase.
One of the best game so far, might be addicted to it