Rihanna is very sweet but also seem to be catty, i.e. Not attending the Grammys opened by Beyonce, not wanting karrieche in the same club, not aknowledging Rita Ora's existence, feuding with Ciara... Who is her main rival?

Ciara. Nothing beats their Twitter feud on ATRL tbh.

Rita vs. Rihanna was a weak feud imo

The one and only that slays the charts with her third single

Herself.

Katy Perry tbh

I don't think she thinks of any of them as "rivals".

The only other Fashion Icon on that list.

I definitely see her main rivals being Ciara, Rita Ora, and Karrueche.

Ci

I really hope that atrl doesn't think that she didn't attend the Grammys because Beyoncé was opening

Beyonce. None of the others are anywhere close to her level of stardom.

She doesn't have any
She's in that legend league alone of her generation

Katy Perry is Rinse's biggest rival.

Of course they do

Her own self.

Then Madonna.

Then Beyonce.

Then Katy Perry

After surpassing Michael Jackson, at this point it's only Mariah Carey and The Beatles.
Of the current girls ICON only competes with herself.

As a singles artist her biggest rival is Katy Perry.

She doesn't see them as rivals

Zendaya.

Comparing Rihanna to Beyonce is more absurd than comparing Rihanna to Rita.