Gyarados was awesome but they had to do things to him to stop him from being unstoppable. A lot of people complain that he should be water/dragon but that would negate the ice supereffectiveness of his dragon type and mean only Dragon moves are 2x effective. That's fine now, but in the first gen the only damage dealing Dragon move was Dragon Rage which does 40 damage, no matter what. So this would make Gyarados pretty much have no weakness'.