A quick bug:

Fire shield seems to have problems, I have a Sapphire charger and two Otyugh attacking the opponent and none of the three take damage. Amateur guess is that it is two bugs, momentum negating fire shield and the base attack value of 0 for Otyugh negating fireshield even after they are upgraded. Unless Gravity don't take damage from fire?

Other than this small bug I haven't had any other problems, its a great game and I wish you the best of luck with it.