Why are you niggers still mad over this?
There is no rule that says he is not allowed to use legendaries, he didn't do anything wrong, he won fair and square.
And his team is not full legendary, he himself said that if Ash were to beat his Darkrai and Latios, he'd most likely easily defeat the rest of his team, which are probably shitmon and he relies entirely on Darkrai and Latios.
Accept the defeat, heh.