I always get exited to get essences, but it isn't possible to make a theme. what if you could? maybe not just have to power to make every essence a theme, but what if there was special essences when you cold choose a theme to make? It could also be randomized or, quite like the fests it could be premade for a certain theme, they could be acquired through fests or something, or maybe just the same way you would regular essences, I understand that they would have to be harder to acquire since they would be worth more then the regular ones, and I am not sure how it would work, but it is just an idea ^^

No support. This would be too overpowered if it works the way I think it does: you can generate a theme to your exact desires, choosing which traits you get exactly and whether they are visible or carried. There is a reason you can't do this on the build-able sylesties during fests. I'd be even less inclined to support this idea if you could get essences of themes already in existence. As much as I'd love to have the control to add newer released traits to the older theme pools.... that's what the trait disruptors and Black Friday wheel are for. If you could just generate the exact theme you want, no matter the cost, there would be no need for trait disruptors or greater genetic mutators anymore.

Really, even as a project breeder who, objectively, would like to be able to get just the traits she wants, this would make things too easy. Once something is too easy, it's not worth as much and doesn't have the same feeling of accomplishment.

So, yeah.... no support. Sorry!