You are evolving fast, level 21 and already close to Midnight Shadow, very good progress indeed.

I'm happy to hear this from such an experienced player.

Today I also played an opponent with a similar tactic, he put a creature with armor in the game and kept reducing the strength of my creatures, this was VERY annoying and every time I put a new strong creature on the battlefield he did this.... I didn't have much to do.

Ye man. Its really annoying strategy.