With just 10 cents worth of rented cards I went from bronze 3 to bronze 1 in just an hour . I just wanted to test if card renting is profitable and yes it's if you rent right cards at reasonable prices. Here you can see the winning streaks
Most helpful card here was the life summoner Lorna Shine with Divine Shield ability. I made 2-3 dec per battle and also got a rare neutral card from the reward chest which is great roi for just a small amount of card renting investment.