[@dabombjk] Well when it comes down to which is more logically combat-able, energy or shadow manipulation, for Therma the energy seems to be the more logical of the two. She tends to use her powers to make herself untouchable or undetectable rather than to fight preferring to use Aikido and her staff. She would need something solid to be able to hit back and a shadow entity isn't the most solid. 

As for when it comes down to morals and backstory, the both hold family to a high standard, so the same family views, but different results would be interesting to play with. Anna trying to figure out just when his standards dropped low enough to become a villain, things like that. I could easily see tradeoffs on who would win in a fight. Occasionally Annabelle would get the upperhand and occasionally Kyle would, it would all depend on the situation and where they were. Especially since Anna is resistant to extreme temps and is capable of lighting things on fire. 


Sorry I rambled a bit, some of that may not have made any sense, but in short yes I can see the two being compatible nemesis.