Anyone no for sure if he is a devil?
Considering that you bought it at a PetSmart, it will be a hybrid cross, as will be the vast majority of RD and/or midas purchased in AB and BC. Once in a while you will find amphilophus being sold from local vendors with pure stock (usually ordered from the US via Rapps, etc) but generally they are crosses between the two species.
Either way, looks like you have a nice little glass banger, have fun with him.

