Who is the strongest esper in One Punch Man? In One Punch Man there are several espers. One of them claims to be stronger than Tatsumaki. Is this true? Who is the strongest esper in One Punch Man?
Update: Gyoro Gyoro(Monster who created Orochi, the king of monsters) and described by Tatsumaki as a "Bag of Flesh" was actually as said, a doll controlled by an esper. While that esper goes by the name Psykos, nothing is revealed about her yet in the manga (Much less the anime).

Spoiler from the Webcomics:


  In the Webcomics of One Punch Man (The most original version which is far ahead of the manga) created by the group One, shows the fight between Psykos and Tatsumaki. It is then revealed that Psykos was once a student/part of Fubuki's group and was nearly overpowered by Tatsumaki until the Cadets of the Monster Association attacked Tatsumaki. While defending herself against the Cadets, she didn't realize that Psykos was about to attack her until it was too late. After Tatsumaki was defeated by the surprise attack from Psykos, Fubuki comes in and attacks Psykos, which she comes out of victorious.


In conclusion, we could say that... (Spoilers)


  Fubuki is the strongest because she won against Psykos who defeated the "strongest" esper Tatsumaki, but seeing as Psykos was weakened and Fubuki had focused her training on defense against overwhelming psychic strength, they all were strong in their own ways. Tatsumaki had the overwhelming resistance and raw power to crush enemies, while Psykos and Fubuki used subtle techniques like doll manipulation (Gyoro Gyoro), and scattering the psychic waves respectively. However, as User Gary Andrews 30 pointed out, Tatsumaki was shown to be more powerful in several more instances and Fubuki's simple scattering technique didn't count as power.


Psykos's character page:


   https://onepunchman.fandom.com/wiki/Psykos