The 7 Devils(Originally said to be were 6 members) are a Villain Group who were reputed to be the most powerful and ruthless Villains in the universe. According to Doctor Greyman it took 300 Heroes to capture them and imprison them a special space prison cell. they were soon freed when someone crash into it. Desiring to fight the Heroes of the plaza they split Mr.Gar's body into pieces to force K.O and the others to fight them. They first appeared in OK K.O Graphic Novel series.
- D-bull- The leader of the 7 Devils(Villain Level:-16). He is a Charging bull-themed villain, he is very large has a scar his right eye(kinda like Lord Boxman's robotic eye) and curved crystallized horns on both side of his head, he split Mr.Gar's body into seven pieces as to force the heroes of the plaza to beat them all in 10 days if they want to save him.His Villain level is -16 while his Strength Levels are 10,000,000, which is 10 times that of Mr.Gar's.His techniques and fighting style usually rely on his immense strength and power, but in tight situations he can lower his power in order to become faster. Additionally, he specializes in brutal fighting and has a spike on each knee. On the other side though, he is quite clever and will often lure his opponents into wasting stamina.
- Mp3 King- A Villain based on an ipod(He resemble an iPod Classic manly the 4th generation one),and the weakest of the 7 Devils(Villain Level:-4.2).He has the ability to copy the abilities of a Certain Hero or Villain that have been downloaded into his playlist. His finishing move is his Crescendo of Doom where he plays music in his opponent's ear so loud is it causes them to pass out.
- Galxaso- A Villain covered all in black and a giant hole in his chest in place of a Heart(Villain Level:-7) He possessed the ability to travel through shadows and the hole in his his chest lead to another dimension,which he could suck his opponent into like a black hole. He was originally the leader of the the group until they got there 7th member. He reappears in the Dream team Tag arc of the graphic novel series where he teams up with Cupid forming the tag-team: Heart & Heartless
- Nerconancy- A young Blood-thirsty Witch and fortune teller, she ''appears to be youngest member of the 7 Devils(Age: 14-16(actually she 1400 years old), Villain Level:6.8).She use an Paralysis beam emitted from her eyes,has an technique of scattering her body around and making them float,can use her floating head to bite down on the opponent and as finishing move she can wrap his opponents/victims in a mummy packaging and then drinks all of their moisture and flesh with a giant straw.
- The 7 Devils are heavily based on the Seven Akuma Choujin from Kinnikuman.