Verse
Acxa Kogane! She was took by Krolia when she was born, She looked too much like a Galra to even be kept on Earth..thus leaving her more human passing fraternal brother and then she went into the Blade and she was put down for not looking 'Galra' enough.
All the bullying was growing aggravating so she finally confronted her Mother which resulted in a huge fight in which both of them shifted apart and that's when she ran off- into the Galra Empire in which she got discriminated against once more before joining Lotor and his gang of fellow outcasts
Bladeverse
In which Acxa didn't let her curiosity affect her and kept her mouth shut and stayed in the Blade, though she's known for disrespecting authority
Reverse!
Lotor and his generals stumble upon the Red Lion in one of the Galra chambers! Lotor sizing the chance to finally rebel against the Galra Empire tried to open said Lion which...didn't work until Acxa decided to bang her on the force field in frustration which not only alerted the guards but with a mighty roar she let them all in! Red then led them to the Castle of the Lions and honestly Allura wasn't exactly thrilled with working with Galras..but she and Coran ended up close friends with the generals and they're considered family after truly spending time together.
With Narti in Green
Zethrid in Yellow and Ezor in Blue
And Lotor and Acxa in in Black and Red they form Voltron! The final battle was nearing and they were facing against Zarkon with Allura going solo with the witch Haggar.They won...but Lotor went missing, leaving Allura to pilot Black in his place...after awhile he returned but..different..he screamed and attacked Narti which was out of character!
And with Narti out of commission they had to rerotate the Lions with Acxa now in Green while Narti is out of commission