Yep; after all, Gravity is about pulling things together, whereas Entropy is about throwing them apart.
There has been a Magnet | Lodestone card in Gravity's CIA before; magnetism, as we all know, is capable of repelling as well as attracting. Not strictly gravitational, but your definition of Entropy is flawed anyway - Entropy is about natural processes running their course and reducing organization. Gravity and Entropy are not true opposites; Gravity, in point of fact, can and does
aid Entropy.
Barring discussion of where this fits
thematically, I am more interested in where it fits best with regard to gameplay and balance. If it will depend on HP, as it does now, Gravity is a poor place for it; however, if it is changed to depend on creature attack, Gravity will still get some mileage, while the benefits of combining it with other elements increase - Gravity has low-attack creatures.
The poll is a dead 50/50 split.