>>25191591>Dusknoir and Walrein, just so Pheobe and Glacia can use their aces in the rematch.I think GF gives Mega Evolutions to the aces of Champions, Rivals, Important Story Characters, and Main Villain Leaders. Like Steven, Wally, Zinnia, Archie, and Maxie.
I think this is how it works for Elite Four. If their ace Pokemon already has a Mega Evolution, thats what that E4 member gets like Sidney and Drake.
But E4 are not entitled to have their ace Pokemon get a mega unlike Champions, Rivals, and Villain Leaders. Thats why Phoebe got Sableye.
With Glacia, she had no Pokemon that had a mega so GF needed to give her a mega but GF could pick anything they wanted.