The ability is interesting, but the attack is kind of basic. I'm not too big of a fan on the art either. It's neat that it's in Castelia, but it would have been cooler to see more of an interation between Amoongus and the city, or have something else neat in the background. Amoongus looks pretty basic too. Overall, this card doesn't impress me.
this card could be sort of useful if you had a few on your bench with devolution spray so you can use the same 1st step to cause the effect. Though this one is greatly outshined by the other one that is able to toss 3 cards from their opponents hand, or cause any status effect by coin flip.