I've got one friend with a level 70 Alpinia. It was pretty cool to see it 1v1 the Wasp boss of 12-5 after the rest of the helper team died and then come out of the fight with more HP than it started with. I've also only got 2 people with rainbows (that I know of) as allies, and it's the same 2 that have always had them. Although one of them has at least 2 6-stars and is probably not a free player.