Hey! Thanks for coming back and playing again and for taking the time to leave such thoughtful feedback.
1. Essentia triggering when selling held unit: Haha this is an interesting surprise! I've been trying to make things as systemic as possible, and I didn't know about this effect. I'd like there to be weird secret things like this in the store phase, but i'll have to think on whether this one makes sense. Possibly changing the wording of Essentia might help.
2. Power curve: I totally agree with you here - I do plan to do something with unlocking units and playing against units you don't own. I think a tier system could also be viable. And for sure the actual pool of units is quite small compared to what I'm eventually hoping to have.
Thanks again!