>>42509831Red never changed. Just the context. He's always just been a guy who never talks and is really good at training Pokemon.
When you meet him in gen 2/4, he's alone on a frozen mountaintop and then he proceeds to battle you with the highest level team in any Pokemon game so far.
When you meet him in gen 7, he's with Blue who acts all casual and even teases him by calling him a gossip.
Nothing he does is different, but one makes him look edgy and mysterious and the other makes him look like a mute sperg.