The game has been here for a few years with the same rules about upgrading champs.  That makes those of us who have been a while CRAZY.    lol

To be fair if we've been here this long at least something has to be wrong with us.

So OP: You don't want to sacrifice champs you've built. You'll hear the term "Chickens" and "Food" in the videos by CCs, they aren't always referring to the chickens and feasts. They're talking about Rares (usually) that you rank up with other rares till they're rank 5, to then "Feed" them to the Champ that you actually want.

Now it does take a LOT of Rares to do this, and brews if you don't want to level them in campaign or dungeons. 4 rank 3 Rares gets you 1 Rank 4 rare. 5 Rank 4 champs gets you 1 Rank 5 champ. So basically, 20 Rares with this method will get you 1 Rank 5 Rare champ to use towards ranking the intended champion to Rank 6. 

Also you should be getting chickens from Tournament and Event rewards to use, as well as CvC. 

Lastly, if there's Champion Training going on, you want to level (usually with brews) the champions before you sacrifice them. There's differing opinions on this, but I use 1 brew to make my Rank 3 champions level 10 before I sacrifice them, I use 3 brews to make my Rank 4 champions level 18 before I sacrifice them and so forth. That way you're getting extra points and they really add up.

As a new player, I can totally understand how it is overwhelming to think that you need 100 Rares to make 1 Rank 5 champion Rank 6. Keep in mind you'll be getting Rares from Mystery Shards AND you can use Uncommon Champions in the same way. 3 Uncommons get you 1 Rank 3 champion, so 300 Uncommon Champions is way easier to get than 100 rares early on. 

Correction to my first statement: You will EVENTUALLY get to the point that you'll sacrifice champions you've built, you'll even start ranking up and sacrificing Epics too (and there are a LOT of garbage Epics unfortunately). Never EVER use Legendaries to rank up other champions. NEVER. There'll be better uses for them like Faction Guardians or turning them into Tokens for the Token Trader when you get duplicates.

Mods - spampost on first response.

Got it, thanks.

Another option to consider, keep your "booked" champ and use as you see fit, and take your lvl 12 champ to 30, upgrade him to a 4star, and use him as a chicken for another champ later on.

https://xender.vip/

Well you can Just wander over to the CASH SHOP and LVL up really fast without doing all the Sacrafices cant you,, Just go BUY Some *XP Barrels* and Some **FEASTS** and Some Chikens .. and Some Sacred Shards, and Void Shards and Ancient Shards, It is so Easy to NOT be a Free to Play Player, or you can just Build up like the rest of us without Money that are FTP and go through the game  (( and NO this is not a Spam Post or a Reddit or Bot either ))