Starfire or Kory is central to the fate of Brother Blood and his plans in season 4 of Titans and she chooses to give her life for the greater good in the end.
Soon after Lex Luthor’s death, Conner finds a book inside the temple of the cult of blood that he’s supposed to give to Dick. The book contains ancient Tamaranean and Dick knows someone who can translate it.
The book tells them about Trigon’s horn and how Mother Mayhem plans to use Sebastian to summon the devil but it also contains a prophecy claiming that Starfire will sacrifice herself to save the world.
Dick insists that they’ve proven prophecies wrong before but Kory tells him that it might just come true. Her blue light powers appear to have extreme capabilities according to the researchers at S.T.A.R. Labs and she also has visions or dreams occasionally.
After searching for Conner leads them to Mercy Graves, the Titans learn that Lex Luthor was researching Starfire’s blue light as well because he too believed it was the key to stopping Sebastian.
They find a bomb that can be infused with her power but they do not charge it completely and it fails to stop Sebastian before he takes on his final form as Brother Blood.
Putting things to rest
When Sebastian reaches S.T.A.R. Labs, he reveals his intentions to open the wormhole created by the researchers and destroy Earth and Tamaran by making them collide. He needs Kory’s power to charge the wormhole and uses mind control to bring her alone.
His plan is thwarted by the Titans and Dick suggests throwing Sebastian through the wormhole and sending him to some unknown corner of space but Kory says that he could return one day much stronger.
She says that it should be her to end him as it was prophesied and grabs Sebastian before flying into the sky. There is an explosion of blue light in the night sky and everyone assumes that Starfire is dead but she flies back down a little while after, now with her powers back to their original state.