This is the first idle game I can get behind. I enjoyed the original bushwhacker, and it is good to see you applying your core world to the idle gameplay in an interesting way!
My suggestions would be as follows:
1. When characters get gear, have it appear on them. When you get the dark feather, the Phoenix could have one of it's feathers turn black.
2. More formation and type synergies (royalty, beast, myths, males, females)
3. Each character having a unique passive skill for when they are not in formation. (tweak numbers as needed).
4. Just a thought that if you click on the characters themselves you could make ...something... happen. Perhaps just an animation but also an active skill or combo of skills. Perhaps tied in with the bushwhacker's clicking?
Even at this stage its an obvious winner, keep it up!
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Glad you're having fun! Thanks for the feedback. =)