..Antimatter is matter that consists of antiprotons, antinuetrons, and positrons. So, converting matter into antimatter (with the supernatural spell, Antimatter) would not change the mass of said matter, but it would invert it's electrical charge. The point I'm making is that charge and mass are comparable to a creature's power and HP in this circumstance (where a spell would be changing the make-up of a creature).
However, I still don't understand how your hand could be metaphorically paralyzed if you can still place them.. Or how the venom would spread to your cards in the first place.. Or the correlation between a paralyzed hand of cards and damage being dealt to the holder of said cards. This is obviously not the case. The cards are obviously not the subject of poisoning or paralysis.. We are not discussing metaphorical toxin..
A spell is less likely to be considered unrealistic in a game because spells are already supernatural. They do not claim, in the first place, to be of scientific nature. There is, however, a science behind toxins.
I don't see why changing neurotoxin's mechanic to something more realistic and fitting can't also be the same solution to balancing or "nerfing" Dune Scorpion. I am indeed offering ideas that realistically nerf this card as well as putting in my two cents regarding the unrealistic mechanic that is currently in place.
However, If I'm discouraged by you from posting such opinions on this topic, could you please direct me to the section of the forums that is meant for such a discussion?