I wonder if Illias was actually onto something there. Maybe his comprehension ability has a hidden drawback, like the more he "comprehends" a target, the more he is influenced by it or becomes like it.
Oh it'd be interesting if it ends up being MC vs other intelligent isekai'd people under different factions all as strategists etc, maybe some factions become allies, some are neutrals and some are enemies.
@daime17 demon race is considered as a default because they are usually seen and/or needed as antagonist... @Weetch as for katana, there are some titles boasting about it but its not really that common as most of isekai are just boasting about MC OP skills... And is not like MC can/will use it since he doesn't have combat abilities... At best, it will only be introduced and will be given to other person just for a sake of screentime and will be brushed off after 1 chapter...
There are also some titles that mainly focused and/or exaggerating about katana though... But i (probably most of the readers too) considered it as a minority, like that peculiar 'Makenshi no Maken Niyoru Maken no Tame no Harem Life' and probably konjiki no word master (mainly its about hiiro's word skills though)