The CW's Arrowverse is about to make history once more in the fourth season of 'Supergirl', as transgender activist Nicole Maines steps onto the show in the role of Nia Nal, aka Dreamer. This means the show will feature television's first transgender superhero, and she's not the only new member of the cast set to make a splash.

Nicole Maines makes her 'Supergirl' debut in season 4Nicole Maines makes her 'Supergirl' debut in season 4

Nia is described as being "a soulful young transgender woman with a fierce drive to protect others," and someone who will go on a "journey this season" which "means fulfilling her destiny as the superhero Dreamer". Bringing such a character onboard furthers the inclusivity that the Arrowverse is renowned for, and will see Maines pave the way for other transgender artists like her to tackle roles such as this in the future.

April Parker Jones has also signed on to play "hardline career military woman" Colonel Haley in the show, whilst David Ajala steps into the role of Manchester Black, described as "the type of guy who brings a knife to a gunfight and still walks away the winner."

These three new names join the already-announced series regulars Jesse Rath and Sam Witwer, who'll play Brainiac-5 and Agent Liberty respectively, and show just how far 'Supergirl' has gone since its earliest days on CBS. Now, with a whole host of heroes, villains, and characters that slot in somewhere in-between, incredible stories can be told like never before.

Greg Berlanti, Sarah Schechter, Robert Rovner and Jessica Queller all serve as executive producers on 'Supergirl' season 4, with Berlanti Productions producing in association with Warner Bros. Television.

More: 'Supergirl' Star Melissa Benoist Calls For Entertainment Industry Change Following Sexual Harassment Claims

We'll bring you more news surrounding 'Supergirl' season 4 as and when we get it. New episodes start on The CW in the US from October 14, in its new Sunday 8/7c time period.