User blog comment:Onida DSTY/Strongest Overlord Characters/@comment-36770034-20180902191924/@comment-34598988-20180914225610

the difference between a level 100 and level 90 world boss would be extremely small a level 90 could be equal to 27 players while a level 100 is eual to 30 but the main reason i say the campain world boss was likely level 90 is because level 90 is the soft-cap in the game

i cant remember where but it was stated by ainz that its extremely easy to gain levels up until 90 so 90 would be the soft cap and most enemies in the game would be level 90 like the raid bosses from nazarick its pretty likely that the campain boss would also be 90

(but this is just my assumtion)