Shadowverse

Just had an epic match in Runecraft. My opponent (Shadow) played one follower (2-1) and one spell (Dance of Death) in six turns. I didn't play much either, because I had all sorts of cards like Hamsas and Red-Hot Ritual, which don't make sense to play if the opponent doesn't have any followers.
In the end, I put out Merlin, buffed him twice with +2/0, attacked, and the opponent rage-quit. I still don't understand what cards he had that he couldn't play...