I want to make this as short as possible, basically healing takes during your end turn while you're attacking, I suggest that you change it so that healing comes before attacking. Simply because, I have had many opportunities to get E mastery with say 95 HP on my last turn with a SoG on the field, but because the opponents HP is too low, it wont heal in time to raise mine. This gets quite annoying because getting the extra 11, or 21 coins etc makes a lot of difference, especially considering how much it happens to me and god knows how many other.
This is just a suggestion and it would be nice to see it pull through, please discuss.