Raksha's timeline seems a bit weird. Orthozora's flashback showed her getting decapitated by Voltekamui. And Crimson stated in chapter 36 that Starlia seems like Raksha's "reincarnation". But he also stated in the same chapter that Raksha became a dragon slayer monk, which on the other hand didn't seem to be something that Orthozora witnessed before he was dragonified.
So if I had to put it together, it looks like Raksha: recruited human Orthozora and Arnold -> started her rebellion -> got defeated by Voltekamui, Orthozora and Taratectore come to be -> didn't die, got resurrected by Carla -> joined the Sun cult
It makes the most sense to me, but doesn't explain why Crimson and Starlia spoke of her like she had already passed away. My guess is that the "reincarnation" line is either a mistranslation and it was meant to read something like "you are the spitting image of her". Or Daiki just retconned her death. Voltekamui's decapitations being non-lethal isn't unprecedented after all, but Crimson should've known from the start that Raksha is very much alive given his role as the Oracle of the Sun cult..