I like the idea, but what exactly is the point of forcing a duo for light/entropy when the same thing could be accomplished via packing chaos seeds/powers? Unlike, say, an Otyugh or EE, this skill is not repeatable except on new creatures. So if, say, a lava golem was on the field and the first present didn't do anything, you would have to play another Santa to do anything. If it were my card, I would remove the "one cast per creature" and just up the cost to 2.