WAIT SO SHE DIES IN THE END ANYWAYS?? No happy ending??
SPOILERS
No, she's still alive now, but her destiny is to die after her powers get out of control. Nina and Alisha are both reincarnations of the star goddess, because the previous reincarnation had her soul split into half after the suffering she endured. Nina's parents knew her fate from the start, and they told her that she has to find the person she loves and ask them to send her off, Nina only remembered it now. Sett told her that he'll do it for her, but I don't think Nina will die^^ There's some lore about Galgada and how they worship a different great god, I think Sett will be connected to it, his mother was a priestess
Big spoilers here
Nina loves Sett, she even told him in the latest chapter. She refers to Az as her first love, and he is important to her, but not as a lover. Again, pretty big spoilers here, but the important reason why we had to know who Nina loves is because that person has to kill her when her powers go out of control. So even if Nina loves Sett, their time together is limited.
Also, you can read this manga for free on the official Km@nga app (Kod@nsha's manga app). You can get points by scrolling through a given chapter each day, and you can also watch 3 ads. It doesn't take up much time and you can read anything on the app for free if you have the points or daily tickets. Finished series/some shounen titles can be mostly read with daily tickets. So you can support the author legally for free.