The reason why this story is so frustrating to read is because author is unable to write a good plot, so they artificially create plot progression and mystery by choosing to make all the characters hide information. Astaroth hides information, Karvis hides information, MC hides information. Demon contracts all doesn't state the price upfront before the contract is made. Instead of proper communication, nothing is shared so it seems like characters are just being dragged around all over the place.
And not sure if the webtoon chose to skip explanation from the novel but we aren't told that Karvis could fuse or alter skills, it just suddenly appear in the story. Author also tries their best to nerf the MC by making him not use or level his other skills like mana absorption which should absolutely be OP against boss or elite monsters who are a chunk of mana. If he could use mana explosion on monsters' mana, why isn't he able to absorb them? At the beginning of the story it was said MC could learn new skills by fulfilling conditions or repeating certain actions but this seems to have been forgotten almost immediately.
Alot of readers always complain that MC is dumb but honestly it's more of dumb writing from the author since all the other characters are the same. Every time there's a fight where MC have to save his comrades or strangers, they just stand around in shock while MC blocks the hits instead of running away or helping to fight back. Everyone literally has negative plot armor in this story. Just compare the actions of other characters in the story to MC and you will soon realize everyone is pretty much the same in IQ. Shame that even visuals can't help support the series since it just got downgraded in season 3.
