Halloween started off as a mask ego made by Old man Hwang and was given to Gi-Gyu just after the battle with Leviathan when Eden was first declared. It gave Gi-Gyu the ability to shapeshift into a player he killed/had the ego information of. Yet later on it became a skill that Gi-Gyu could use because of his sync with Rohan (Roger Han). This also meant that Rohan's main skill changed from the ability to transfer his consciousness/soul to a corpse, into Halloween's shapeshift ability. There is even a scene where Rohan uses this Halloween ability to shapeshift into Gi-Gyu when in Rome.

When Botis is struggling to evolve because all of the other egos are getting stronger faster than him, he receives an upgraded version of his cocoon from Paimon. He then states that knew his cocoon was needed for his evolution but 'couldn't dare to covet what was his masters', insinuating that Gi-Gyu kept his cocoon somewhere since they first synced. The main issue here is that Botis seems to think that Gi-Gyu had his cocoon all along. Since his body was eaten, Botis' ego was placed directly into the cocoon and the whole thing condensed down to become his new body. Even if I'm misremembering and it was just the magic in the cocoon that made Botis' new body, not the cocoon itself, why would Gi-Gyu just keep it hidden somewhere when Botis felt like he needed it to evolve? Was the cocoon just sitting in some corner of the gate all this time while Botis was misunderstanding that Gi-Gyu would be upset if he used it to evolve? Even if I did misremember and it doesn't break the story's continuity, the reality the author suggests makes zero sense.

This has to be the worst one since it involves Lou's backstory. In order to become the 1 true king of hell Lou had to fight against the seven hell kings. It was a balanced fight (1 v 7) until Lou managed to kill one. Satan died and Lou used his body to make weapons that signified the remaining 6 kings becoming his subordinates. Yet, when we are finally given the names of all the '7 hell kings' in chapter 336, we are told that they consist of (1) Belphegor, (2) Leviathan, (3) Asmodeus, (4) Mammon, (5) Beelzebub, (6) Satan, and finally (7) Lucifer (Lou). I would have thought that Lou, being the second most important character in the story, would have have a more solidly defined backstory.

When bringing Old man Hwang back to life as an ego, Gi-Gyu learns that holy swords have life force (aka, are alive). As Gi-Gyu learns more about angels and holy swords, in the 40th floor test he comes to realize that all holy swords are actually just angels. Later, he revives 3 angles from dead holy swords. While there is a distinction between the 3 angels who revived fully (as they received the life root) and the 1 extra sword that just returned to being a functional holy sword (as it only received life energy), that distinction is not made clear. In the battle against Botis, all 3 of these angels turn into their sword forms and stab/combine with El, forcing her evolution in the fight. Yet later, when Hamiel (the last surviving of the 3 angels) is trying to be of use in a fight, both Gi-Gyu and him mention that he cannot become a sword for Gi-Gyu because he'd never be able to change back... for no explicable reason, even though he's done it before?! I think this one is just the author thinking up a convoluted power and not explaining it fully.

As mentioned in the last note, Gi-Gyu brings 3 angels back to life. At the time, he names them Hamiel, Kanael, and Anael. Hamiel becomes the leader of the group, and the other 2 names are never mentioned again, ever. This wouldn't normally be a big deal since they're quite minor characters, and I wouldn't have noted it here if we didn't get an entire chapter dedicated to their funeral. Everyone is crushed, their deaths become a big motivation for becoming stronger, but never once does anyone say their names. Gi-Gyu, who named them, doesn't even say their name while mourning them. It feels so awkward that these characters don't seem to remember their dead friends names. If they were nameless from the start then it wouldn't feel so weird, but since they did receive names, it would have been an excellent time to mention them.

in a world where dungeon gates mysterious appeared 23 years ago, we have a nice guy who for whatever reason is the only "player" (player referring to the certain part of the population who have special abilities and are allowed to enter the tower) who cant lvl up. He currently works as a tutorial for noob players.

in a crisis he managed to clear the 5th floor trail by accident and gain the ability to partner with "egos" (a I sentient being who can lvl up similar to players but resides in objects) he is given his first ego for free who by coincidence becomes a sword ego, he finds another sword ego shortly after and switching his fighting style to duel wield. ⚔️ (As you can see from the cover art) this begins his way to easy journey to OP-hood.

just one issue tho, his mom is dying! And only has a few months to live. In a desperate attempt to get the all powerful exlir, he runs head first into a high lvl maze dungeon despite being only lvl 10. Obviously he gets his ass kicked and almost dies. Lucifer (a high ranking player known for ruthlessness) saves him at the last second and demands he belong to her in exchange for the exlir, he agrees. He swears to get vengeance on the player that beat his ass and their entire association with it.