MArcomage

This card is quite powerful, it can easly discard also rares as fortified castle. I suggest to make it discard only one random "wall +" card (common first). or simply make this card uncommon.

How bout non-rare Wall+?
I believe Undead should have some means of retaliation against Holy.

Holy already has a card that can massively discard 4 Undead hands from enemy hand. This looks a good retaliation. I would suggest though, to change it and instead of discarding +wall cards, to replace non-rare Holy cards with Purified ashes