That picture doesn't feature crystal however so hardly fixes our problem. Either way..

CardCaptor likely would need two of his natures, in order to have storm release. [b]However..[/b] this doesn't mean he has mastery over even one or both of them as far as I know. 

However with crytal release, we can say it's earth release only. In that case, having 3 natures is just simply too much.