If I were to design an In Nomine CCG, I would start by tweaking the rules of Jyhad / V:tES because in my opinion, it has one of the most balanced systems. In particular, rare cards are just different or outright weird, not necessarily more powerful; you actually want less of them. Common cards make up 60%-80% of any good deck. And, Jyhad had a very strong political element. It allows several completely different strategies for winning, primarily rapid bleeding, manipulative voting, and direct combat.
