Meichi Yuri

Meichi Yuri is the true main antagonist of the anime/manga Akuma no Riddle as well as the true Big Bad. She is the unknow chairwomen of Myojo high and is responsible for the creation of Class Black.

History
Not much information is given about Meichi's past, but it is know that she and Haru are part of the same clan, and the she was the one who created Class Black which began when she took part in the same project which lasted 6 days. Also according to Nio Hashiri, she saved Nio when she was young and took care of her.

Akuma No Riddle
Meichi was first seen after Tokaku and Haru battle against Sumireko and tells Nio the it is time to inform them of the true purpose of Class Black. Later the next night Tokaku and Haru are brought before Meichi who informs Tokaku that Class Black was actully a test to see if Haru could use her power as the "primer" to survive Class Black and someday take over their like Meichi did. Maichi also states that the reason Tokaku decided on the first day to protect Haru was because of Haru power to control people, but leaves it ambiguous as to whether or not Haru did this intentionally.This causes Tokaku to try and kill Haru to see if she actully cares about her or if it is just her primer power.Nio (who was using hypnotic suggestions to take on Tokaku's appearance) also attempted  to kill Haru but was stopped by Tokaku. Haru was later stabbed by Tokaku, after Haru charged at her with Nio's blade. Meichi shows up after the fact to ask Tokaku what her wish is as the winner of class black, to which Tokaku responds by telling her that she can no longer get the one wish that she truly wanted. It is later revealed at the end of the school year that Haru and Nio survived their attacks making Haru the sole graduate of Class Black. Meichi was last seen talking to Nio about surviving her attack.

Apperarance
She has long red hair and pinkish eyes. She wears a black suit with a white collar shirt underneath.

Skills and Abilities
As part of Haru's clan she likely possess the Queen bee power, also know as the primer power. It is implied that she used this power to save Nio. It is unknow if she has any combat skills.