[Rebirth cards are no longer available. If you owned a RB card, you will now find the regular card in your Collection.]
Rebirth, or Rb, are cards that are made to update the artwork of older cards in Urban Rivals.
Most cards that got Rb'ed are due to the fact that their old artworks look old or have the same pose/looks every level, making the cards look underwhelming/ridiculous/stupid. This is comparable with Brandon, whose old artwork's levels are simply him changing his shirt color, while his new artwork, Brandon Rb, has him looking twisted every level.
This trend stopped in December 13, 2016, due to an overwhelming community vote. Thus many Rebirth cards' artworks replaced the original cards, as the original artwork is now in the museum. Cards will still be redesigned, but their artwork will be directly replaced.
It's also noted that Rb cards are not different from their normal cards, thus it's often better to just get the older cards to see their new artworks.
Some cards that where Rb'ed can still be Cr'ed, like Striker Cr, GraksmxxT Cr, and Ratanah Cr.