yeah i like the idea of doing 1 dmg to all creatures, like an unstable gas. I'm just curious as to the effects of the damage on other burrowed worms. Really what i'm wondering is if you burrow one, then put another, does the first get damaged? because if not, stack this with a diamond shield, put in a few time towers, a couple graboids for damage and a protect artifact/eternity, seems like a pretty solid pvp deck where you can stack the dmg reduction to get creatures to low dmg, then add the -3 dmg from shield. ultimately, if the dmg doesn't hit burrowed creatures graboids/shriekers/this card would not be damaged and the only effects would be negative on the opponent.
edit: reading jmizzle's explanation leads me to believe this idea is plausible at least. hopefully if this card goes live i can try it out in the game