The concept of reincarnation paired with magic has been explored in several TV shows, and one that immediately comes to mind is 'The Twelve Kingdoms.' It's an older anime, but the way it blends rebirth with a richly detailed fantasy world is still unmatched. The protagonist, Youko Nakajima, is literally pulled into another world where she discovers her true identity as a queen. The magic system isn't flashy, but it's deeply tied to the lore, making every spell and creature feel significant.
Another gem is 'Mushoku Tensei: Jobless Reincarnation,' which dives headfirst into the reborn-with-magic trope. Rudeus, the main character, gets a second chance at life in a fantasy world and grows up with both his past memories and newfound magical abilities. The show doesn't shy away from the darker aspects of rebirth, like guilt and self-improvement, while still delivering breathtaking magical battles. It's a balance that few series manage to strike so well.