Got several two star champions but only a few 3 stars. However after getting them that does not give me enough to upgrade champions to four star except for one champion. I played at least 500 12.3 battles. Got mostly gear to sell. Got about 3 millon in Silver. That was good. But getting the 3 star champions is a pain.
A10C, let me explain how the usual process goes for farming. I'm going to use a bunch of screenshots to try to make this easier.
First - farm Campaign on Brutal 12-3 with food, like this. Notice that I have one champion who is level 60, and three others that are level 1. Those three will become food.
Next, use either the market or the summoning portal, to get champs that you can use as food to rank up your trained food:
After that, go into the Tavern, and rank up your low-level food, so that you can use it to feed higher level food. Please note that in ALL of the below screenshots, the champs that I am using to upgrade rank are ALWAYS level 1.
Two-star food to three star:
Three-star food to four star:
Four-star food to five star (incomplete because I don't have enough of them yet):
Lastly, use the food you've been ranking up, to rank up the champs you actually want to use:
I have sped up the 10 runs needed to take them from level 1 to level 20, but you can see how quickly it is possible to get 3x food that will take a level 30 up to rank 4.
Assuming you have the XP boost on, it takes 10 runs to get from level 1 to level 20, about 23 runs to get from level 1 to level 30, and about 52 runs to get from level 1 to level 40.
When you did the 500 runs of 12.3, if you had been leveling food you could have had about 50 rank 3 food