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

the NPC wouldnt need to have a level advantage to 1v1 a player for example a level 90 raid boss could 1v1 a level 100 player easily i wouldnt be suprised if a level 80 raid boss could 1v1 a level 100 player 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 since every player (no matter how skilled) would have to beat it in order to complete the campain and they would most likely befighting it at level 90 since that was the soft-cap it would have to be an easy mode world boss when compared to the others

(but this is just my assumtion)