Something like Super Gene or Colossus Hunter or The First Hunter, where the world has monsters or other enemies and the MC's job is the kill the biggest/most powerful of them
most powerful monsters not in the final boss sense, but like ss-rank monsters in the naruto system just to give you a scenario: 'The world has been invaded by monsters, mc gets ahead of the other humans by some means (eg. first to get system or some op title/skill), there are some monsters which are skyscraper huge and are city-killers, mc gets a class/job/mission to kill these monsters, which are like double the level of the mc'
So like Translation: Solo Leveling, The hero returns, Original: Paragon of destruction (not sure about this one, its on-going) Return of last survivor (Big boss zombie monarch originally, you would understand as you read it) I'll add as i remember.
There's that I Eat Tomatoes one where MC has some weird OP body and then he gets a microchip or something and then he absorbs the powers of some extremely rare space lion and then I dropped it so don't know what other insane power ups he gets but he's always the underdog in CN MC fashion. Swallowed Star.
i know that one. i've read all the works of i eat tomatoes and know i'm a little fed up of his writing style. but thanks anyway!
Her Summon - a manhwa the story is about a weeb summoned to another world as a familiar. The art is beautiful specially the environment and the monster design are amazing. Some of the enemies are exactly what you're looking for apex predator that is even bigger than a mountain and the artist did an amazing job at portraying how huge they are.