This is absurdly OP. To wit:
Entropy/Death "Hydratic Equation" Beatstick
Mark of Entropy
8x Bone Tower
4x Amethyst Tower
6x Maxwell's Demon (elite)
6x Hydra (elite)
3x Bone Wall (elite)
2x Condor
Get out a Maxwell's or two. Use them to keep major enemy threats at bay until you get a Hydra or two out. Then, every turn, you mass-produce Hydras with your Maxwell's, using them to generate Bone Wall tokens and huge Condors along the way. Not even Rain of Fire can stop you, because it just doubles your number of Hydras, and the Maxwell's can survive an RoF no problem. It'll walk over Diamond Shield, walk under Gravity Shield, and is basically limited by the number of creature slots available to you.
I'm sorry, but the idea of ANY creature that splits instead of dying is OP -- and giving it a 6 attack is just absurd.