I like, very Zergy. Other potential is giving it an ability like endow which targets a creature. This would be useful for duos which use their mark as the sole quanta source (eg graboid builds)
Gravity: Issues are black hole and momentum. Gaining momentum would deal with armagios and be thematic. But I think that's what you were implying with Earth (imo you should change "damage can't be reduced" to momentum.)
Being poisonous to consume would be good for Otyughs, and applies well with a life card. Either that or some active that reduces a target's attack power
Aether: Spell damage. This way it stays away from flat out permanent control
Life: Reducing incoming damage by 1 would probably be too strong. Perhaps 2
infect?
On entropy: Raising health to 7, as you do with fire, would keep it safe from Maxwell's Demon. Personally I feel you'd rather give it more attack against fire. But you're trying to counter antimatter. Maybe being 6|6 with constant attack? Other effect to play well with is mutation. Personally I feel Anteosaurus should be designed to synergize in a life/entropy duo involving mutation. Having it somehow consume the mutation spell like a Chaos Power and/or getting a random active would be neat