Oka is the Peace Hashira she has five forms 1st form: friendly conversation 2nd form the sound of a thousand dove wings, 3rd form angelic therapy 4th form Peace in and 5th form Peace out which is kind of the same Peace in allows her to teleport when needed and peace out allows her to kill a normal weak demon quickly and makes her hold up the peace sign and walk away but for stronger demons it just stuns them long enough to behead them and she is somewhere in the middle for her rank as a Hashira. Friends/family: Mitsuri, Tanjiro, Nezuko, Shinobu and Zokomo ( My other demon slayer oc) and she does not die in the infinity castle battle and she get's saved by Zokomo and they became friends 0.2 seconds before Muzan killed Zokomo.
Credits to @IndigoBunnii for doing the art for Oka