Prome O has some reasonable psychic powers, but they are nothing next to Pikachu’s strength. Pikachu may very well be the fastest Pokemon in existence and he is certainly one of the strongest ones. None of Prome O’s shields will be good enough to stop him and I doubt they would even slow him. Pikachu has proven time and time again that he doesn’t even need a Mega form to win fights. He’s just about unbeatable as it is. Pikachu wins.