Did you ever hear the tragedy of Darth Plagius the wise? I thought not. Its not a story the jedi would tell you. Darth Plagius was a dark lord of the sith so powerful and so wize, he could use the force to influence the midichlorians to create life. He had such a knowledge of the darkside he could even keep the ones he cared about, from dying...
He became so powerful that of course the only thing he was afraid of was losing his power which eventually of course he did. Unfortunately he taught his apprentice everything he knew then his his apprentice killed him in his sleep.
Ironic. He could save others from death, but not himself.