Shikkakumon no Saikyou Kenja

Related to magi. Devils (evil forces) and humans (justice/light) conflicts each other. Academy for magicians. The protagonists have great power. Kenja no Mago MC still understanding how powerful he is exactly and, in contrast, Shikkakumon MC has a better idea about his true power. The two deals with reincarnation- Kenja isekai'd and Shikkakumon reincarnation through past life in the same world. Looking for humans X devils in a academic formation/school learning environment for, from times to time, big baddies make a call and some random battle starts? Maybe some romance in the meantime? Those animes are for you. 

its an isekai where the new world has magic, but the mc is ahead of everyone else because of advanced "modern" knowledge 

- MC overpowered also reincarnate (the different kenja mc is basically from our world and this anime mc basically reincarnate from same world) - Magnet chick, 2 chicks suddenly appear out of blues love to him - Totally looks kenja no mago from episode 1 - both anime academy arc start with MC show off and demon/enemy appear nowhere, MC save it and thats it 

- Both has op mc. - Despite being strong, they go to the academy and meet a sweet girl. - Mc's are at war with demons. - Mc's both use powerful spells as if it was nothing.  

In both anime, the MC reincarnates into the same world after a very long time (the reasons are different). The MC possesses great knowledge of the world. Despite being one of the most powerful, they both make team with a few people and dedicate time to help them improve. I've got the same vibes from watching them, apart from Maou being more gory at parts. Maybe Shikkakumon has a more of generic basic setup, but I'm sure if you liked one, you'll like the other as well. 

The strongest person reincarnates in the same world but in the future where magic and power levels have declines so they are still the strongest. Everyone looks down on MC's but every time they surprise them by whowing them the difference in stregth. 

Both are similar for the MC's background story. Ancient conflicts between humans and demons. Schooling for magicians and others with magic skills and combat. If you ike powerful protagonist rekting traditional schooling rules and making his name through a supposedly "peaceful era" both are good choices. Just pointing out that, besides this, Maou Gakuin MC is a Chad and Shikkakumon MC still a Padawan. Overall, the two are powerful for the average cast though. 

Backstory of both series are similar: powerful MCs that gets reincarnated in a different age to find everything is now different. They now try to prove that the power they have, which is considered weak, is actually much more powerful than the status quo. 

Both features MC (Myne and Mathias) who get reincarnated into a child's body while retaining memory from their previous life. Myne and Mathias use their knowledge from their previous life to develop new technology and improve the lives of others around them. There is some difference between these 2 anime: 1. Weakest Crest is an adventure isekai where it features combat and death while Bookworm is a Slice of Life isekai featuring very little combat. 2. Weakest Crest is a fast pace anime where Bookworm is slow. 3. Myne is a female while Mathias is a male 4. Myne and Mathias use their knowledge in a different way. Myne focuses on introducing technology from her original world. While Mathias uses his knowledge of magic to enhance his party mate's magic.  read more 

Both features MC (Ryouma and Mathias) who get reincarnated into a child's body while retaining memory from their previous life. Ryouma and Mathias use their knowledge from their previous life to develop new technology and improve the lives of others around them. Ryouma and Mathias are considered gifted for their age. There is some difference between these 2 anime: 1. Weakest Crest is an adventure isekai where it features combat and death while Grace of God leans towards Slice of Life. 2. Even though both features combat. Weakest Crest features significantly more combat than Grace of God 3. Ryouma and Mathias use their knowledge in a different way. Ryouma uses his knowledge to open a shop while introducing modern technology. While Mathias uses his knowledge of magic to enhance his party mate's magic.  read more 

Both features MC (Mathias and Mile) who get reincarnated into a child's body while retaining memory from their previous life. Both anime starts with Mile and Mathias about the enroll to a school, both left school at the first half of the series where they become a adventurer Both Mile and Mathias have overpowered combat abilities. Both form a party of 4 and travel around the world. Both features combat, blood, and death. There is some difference between these 2 anime: 1. Mile is a female while Mathias is a male. 2. Mathias embraced his ability while Mile rejects it. 3. Average abilities features a full female party while Strongest Crest have a male in its party  read more 

Both features MC (Ernesti and Mathias) who get reincarnated into a child's body while retaining memory from their previous life. Both use their knowledge from their previous life to improve their combat ability for themselves and others. Both features powerful enemies who are planning to invade MC's country Both are considered gifted by others and well-respected by the monarchy. There is some difference between these 2 anime: 1. Strongest Crest focuses on melee and magic combat while Knight's focuses on mecha.