Therion may be a good Ardbert substitute although you need to swing from the top row if you can so you can protect him properly. Ardbert / Therion need to be able to take cards in order for this to work; a turn one opener is good defense but usually countered by an A side, so you may need to sacrifice them occasionally. Overall though a very good defense deck where you can spring a trap in the last 1/2 turns.