Megami Tensei and its subsequent spinoffs, Shin Megami Tensei, Devil Summoner, Persona, Digital Devil Saga and Devil Survivor, unsurprisingly, have a lot of characters as it is a long running series since 1987.
I am a massive fan of the series, and decided to compile them all into one list, as some characters do not show up in the search function, tags or otherwise. I'll periodically update this if/when characters are added.
Many talented creators have contributed, so I have linked their profiles in the event you like their content. Characters without a profile are by myself. For convenience, in the event you wish to see other characters from the series, I have linked to a wiki page of each games character lists.
If demons have a role in a particular games story; be it a narrative, boss, or side-quest, they'll be tagged in that game (Pixie for Nocturne, etc). If they're just typically random encounters or fusions, I'll just place them in the earliest game that design appears in.
Current update 28/11/23
Added Chie, Kanji, Teddie, Ai, Yumi, Izanami and Aika to Persona 4.
Added Ariadne and Ken to P4 Arena, as well as sorting prior released characters into it now that it has its own category.
Added Kanami Mashita to Persona 4: Dancing All Night
Added Chie's Fighter Armour and Naoto's Coronet Armour to costumes.
Added justTNP's Chidori, Takaya and Jin to Persona 3 and Naoto to Persona 4.
I might release Rise's Arabian armour at some point. I had planned to with this batch alongside the others, but after several revisions it still wasn't consistent and it was holding up releasing the rest. Next batch will be Digital Devil Saga characters.
That's all, hee-ho!