So I started my Grind with 10,674 DEC 
with rentals focused on my best pick splinter (LIFE) at 100% ECR.
After a few minutes, I completed my DQ (Sneak Quest) with not so good rewards lmao:
Next UP: 2nd Daily quest (Fire Splinter).
To be honest, If I got a DQ other than Life, Neutrals and Earth, I automatically change my daily quest but with my luck (which basically counts as 0% -jk), I got Death, then changed to Fire.
After some struggles, I finished my daily quest with less than the first DQ rewards lol:
After hours of grinding, I got a total of 12,012 DEC with 22.18% ECR remaining with total of 95 Battles.
Starting DEC: 10,764 DEC
Total spent on rentals: around 750+ DEC
Remaining DEC Before grind: 10,014 DEC
DEC Gained from Grind: 2,219 DEC
DEC After grind: 12,012 DEC
NET PROFIT: 1248 DEC
Here are my rented cards, (Fire, Life and Dragon for versatility)
Total Power accumulated:
FIRE
LIFE
DRAGON
Here are my Battle logs:
SPLINTERLANDS TO THE MOON!
it's nice to get DEC profit, but playing so many games in a day will hurt your potential for profit on future days, as your ECR is now very low.
Yes, totally agree with this especially when you have single accounts. In my case, I have 4 accounts that I manually grind so the cooldown of my ecr here doesn't really affect me that much! :D
Only Dragon Summoners? Are all these manual rents or did you use the auto-bid system as well? Thanks!
Hi bro! Yes, all of the posted pics are all of my rented cards. I forgot to include the neutrals tho. All of them were manually rented. I haven't familiarized my self on the auto-bid system yet. :)
It is a really good progression.