RileyXY1
Young Battle Trainer
You know how popular Greninja is. Bringing it back will be at the expense of Ash's Alolan team, who will be robbed of potential battle experience that they need.What I was arguing about is that reserves appearing does not necessarily mean that the regional team can't perform well in the League, nor does reserves not appearing during the League guarantees that the regional team will perform better.
And really, Greninja overshadowed the Kalos team more than Pikachu 'during the League'? Pikachu was the one who got 2 wins in both the Sawyer and Alain matches, thus robbing Goodra/Noivern's chances to get wins. Greninja just got more screentime/focus during Mega battles, and was shown defeating the Altaria trainer in the first match(which wasn't fully shown), that's it.
And at the time of the League the series/its atmosphere will very likely become battle heavy too.