Hello everyone,
I'm opening this thread to report what I believe is a bug: I was able to use an AG on a champion already awakened (and max sig. too). It didn't change anything of the champion, but the AG is now gone as if I actually used it. Below there's a video, thankfully I decided to record before trying ^_^
https://www.youtube.com/watch?v=TIdrnaKWJ0o