In “The Rise of Skywalker,” Rey says she simply transferred some of her life force to Kylo Ren after stabbing him with his own lightsaber to save him. Kylo Ren later uses the same Force power on Rey to save her. If this seemed outlandish, it was hinted in “Episode III” that powerful Sith could learn how to prevent people from dying.
https://www.insider.com/star-wars-the-rise-of-skywalker-unanswered-questions-2019-12

