Special K's comments

Sejun is already the most powerful human on earth at this point, he just doesn't realize it yet.

In the novel, he once goes down to one of the lower floors and the worlds top hunter sees him. Sejun's "Aura" is so powerful that the top hunter and his own team can't even look at him or get near. He's basically close to that point already in the story though I don't know when exactly. All thanks to him being around strong people and constantly getting good gear and magic veggies and food. 

As for the enemies, all enemies in this story fall into a few categories:

1. Get destroyed (likely by the real MC of this story, Theo)
2. Get turned into a pet (not even joking, you think hisnfarm is rowdy and full of cute animals now? That's nothing
3. Literally become Theo's slave through a contract

So don't worry, no matter the disaster, our heroes will find a way, sometimes it's absurd but who's reading this for the story, we're here for cute talking animals with a lil action to break things up... The story isn't too bad though. 

As for Sejun getting as strong as a dragon, not that I'm aware of. It's actually a major plotpoint that all of his animal friends, especially dragons, constantly have to go out of their way not to obliterate him on site. To be fair, he should NOT be on floor 99 and the goal was not for him to start throwing hands with dragons.

That said, don't worry about it, all dragons legit obey him eventually, you see he's already got two angry dads on a leash, Aileen loves him and the white dragons son/grandson (can't remember relation) ...You're going to love that one. 

Tl;dr

our heros will be fine