(THINK she's the only rainbow with this)

I'm not totally sure but I think Helenium have one too.

Well, I'm not actually fan of these two but I like them 'cause they're strong. Anemone is overpowered and clearly one of the best 6* due to her skill. Just one of the best skill type imho.
Oncidium is alsoa really good 5* and with speed boost, attack boost and HP drain skill she can be a strong pillar in almost any kind of team.
I don't want to speak for other people but it's why I like them, more than a lot of other girls with a better design or personnality.