Rosalina definitely looks 10x bigger than Ridley, at least.
Anyway, I don't know enough about Xenoblade to say I can actively support Shulk, but he does seem like he would have an interesting moveset. Though I can just watch videos for what all his moves are for research, but I was wondering about his general stats; Is he slow on his feet, does he use his attack power to offset a bad defense, would be be great in the air, would he have any special mechanics like Mac, Rosalina, WFT and Villager, those kind of things.