Tensei shitara Dainana Ouji Datta node, Kimama ni Majutsu wo Kiwamemasu

Both protagonists are reincarnations and excel in magic. They both try to somewhat hide it.  

both anime about a reincarnated shouta with adult mind, who is fascinated by magic and has his own harem  

Both MC's reincarnate as a child into a royal family and possess a lot of magical power. 

The two main characters who like playing games and have intelligence that can rival an all-knowing god, are summoned to another world that contains many games and is based on 10 promises that cannot be broken. 

Both animes are about main character being reincarnated in isekai as a child that is obsessed with some subject. Their both living in their own world, focusing on their pastimes which makes them ignore everything else. Both animes are also light, colorful and make you watch whole series at one go. The biggest difference is that Myne is born in the mob and Lloyd is a seventh prince. 

The main character who is not talented in magic is reincarnated as the seventh prince, he then learns magic to the point he becomes invincible at anything. So far it is not known what this weakness is. 

Reincarnated main character just vibing and getting stronger, Knows its target audience and delivers on every important aspect for it 

Reincarnated main character just vibing and getting stronger, Knows its target audience and delivers on every important aspect for it 

Both the main characters are overpowered, small, blue-haired, and exude chaotic cinnamon-bun energy. Both shows are set in a fantasy setting and are comedies. 

Both of these shows have well-animated psychic/magic action scenes that express a similar style and vibe, especially in later episodes. Both main characters are OP and have a strong dichotomy between who they are in and out of battle. Both shows have a small, floating, supernatural, and somewhat irritating sidekick. The main difference is that 7th Prince uses mild ecchi as relief while Mob Psycho uses gag comedy. 

They have a similar ratio of messed up, fun and wondrous in them, though each are very much products of their era. 

both have young boys as the main charater who is obsessed with some fantasy element, in knights and magic is mechs and in 7th prince its magic. both of them are extremely talented in there areas and tend to creep people out with how focused they are. both improve there areas in ways no-one has thought of before both have MC's that kinda look like girls. both are set in a magical fantasy world where the MC's get reincarnated to live out there otaku dreams in there respective fields. 7th prince has a lot more ecchi stuff then K&M witch has no ecchi things.  

Reincarnated main character just vibing and getting stronger, Knows its target audience and delivers on every important aspect for it 

Reincarnated main character just vibing and getting stronger, Knows its target audience and delivers on every important aspect for it 

Both have interesting powers, strong characters, and similar type of feel when watching. Both are more adult and gritty than what you expect from the animation style. Would watch both on Adult swim.