He achieved immortality by becoming a Force Ghost/one with the Force. Not exactly more powerful in a physical sense, but he can appear wherever and whenever he wants, to give advice to others. Information is often more important than physical strength.
More Sci-fi/Space Fantasy caps please! It's my favorite genre
Interesting take, there is just so much to fit into a two hour movie. Even if there are sequels and prequels, books and comics.. Sometimes tough to follow new characters and their connection. Sometimes the followers like yourself find connection, or just =make them up. Still, quite a universe. More please.