Sorry, I don't really understand your question. I'll make an example.^^
You've got Fenrir (3/4) and Micro Abomination (2/4); your opponent has got Crimson Dragon (12/3), Light Dragon (12/12) and Photon (1/1).
In order Fenrir will devour: Crimson Dragon (getting +1/+1 ===> Fenrir is now a 4/5), your Micro Abomination (Fenrir 5/6) and then the Photon.