The problem you're facing is entirely due to that last thing you said - "Of course they will get ascend or lvld up later on"

Don't run anything without a full team of level 60s, all fully ascended, all with full masteries, and, eventually, all non-legendary champs fully booked.

For Dragon, you can easily have a team capable of going all the way to 20, once you get the gear for it:

• Athel / Fahrkahn the Fat, depending on affinity 
• Melga
• Apoth
• Toragi
• Shemnath

That was exactly my team :D

But i failed damage check (breath) on stage 10 and Shemnath/Athel are same affinity. I woulf have 4 mages.

Hence me suggesting Fatman as a substitute. But the reason you're failing the run is not because of the champs. It's because they aren't level 60. There is a huge difference between a level 50 and a level 60.

I also expect it's unlikely any of them have masteries, which is another huge source of damage / survival.

thats true. Athel has all books/masteries. But i'm very hesitant giving the rest of the team masteries cause im careful with ressources. I got 3 feasts and enough gems for 2 full masteries however.

It was a good choice to max out Athel first, she is a quite good campaign farmer. Not at the same level with Queen Eva or Saurus, but fast enough to do a fight in less than 30 seconds.

12.3 campaign until all members of Krama's suggested team are lvl 60. Forget about the dragon right now. The only relevant content of the game for the next week is 12.3 brutal.

I would only pay the starter gems masteries with gems. Afterwards it is less expensive to run them in minotaur. 

Ok thx :)

Which of those champs would be the mastery prio, and which epic should i gave books first?

 - Fahrkahn the Fat

• Melga
• Apoth
• Toragi
• Shemnath