Pain

Pain is the recognized leader of Akatsuki, partnered to Konan, with Tobi acting as his benefactor. He is the principal figure in the tailed beast sealing ceremony.
[The first and leading "Pain" appearing in the series is actually [Yahiko)(https://anilist.co/character/23050/Yahiko), one of six animated corpses collectively known as "The Six Paths of Pain" that are all controlled by one person's will: Nagato of Amegakure.]