The essence has had a different effect upon my test subjects, making them more intelligent and powerful than ordinary "beasts". My first test subject, however, Germond the Rabbit, turned vicious and uncontrollable. After almost killing me, he had to be put down.
Commentary
I knew that a beast mastermind was the goal, but that's the only preconception entering the character editor. Once I saw him in the steampunk garb, the backstory just fell into place.
I hope the tone of his description reminds you of the writings of Jules Verne or H.G. Wells. The names of his pets were also meant to give the same vibe.
My other beast mastermind, Diddle Diddle had a somewhat similar secondary power set, Sonic Resonance. Both sets provide resistance shielding to their pets and their teammates, but Thermal Radiation also has two healing powers. Diddle did ok with just the power pool heal, Aid Other. I'm sure Pipsqueak would have done slightly better if he had been given the chance.