I agree that the spellwyrm is a really great card for control nature. Not only anti-combo, but also against control deception you can ruin their plans for copying your wisp or generally messing with your hand. Of course, control nature plays a lot of spells too, which means they get to do it to you. I'm thinking this will favor creature-focused control nature the most.

Also love the rust-away card. Straight up zombie hate. Knock out scepter and obelisk for 3 cards and 1 mana.