New heroes and balance adjustments 
- 2022.09.02 14:04 (UTC+0)
My thought is to delay features similar to Awakening and Skill Enhance. Just make them not work yet on day 1. Once the heroes have been around for x days, add the tweaks in stages. That should make balance adjustment easier. Was a new hero weak? Boost their power with above-average Awakening/Skill Enhancement/Other! Did the hero turn out to be OP? Make their Awakening/Skill Enhancement/Other minimal.
If you don't want to change the way the current upgrades are done, perhaps you can add another mechanic that is introduced only after having played a character a certain amount of time. Something similar to the Friendship system (but not exactly like it since gifts can speed that up). Just something any hero can get, but that no player can get on day 1...giving you time to decide whether the character needs a negligible boost or a large boost.
I've always thought that new heroes should be less powerful, anyway. People will play them just because they are new.