These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
God-Mode Sue - Id by himself in his normal mode alone is stupidly godmode. But just for good measure, he has a sword with the power of a god, a state where he taps into his dragonheart for even more god mode, and, just in case that's not enough, he has an even further state where he fuses with Lamia (his sword) for god mode so hard he curb stompsGod (that's right, with a capital G). Only loses once in the entire manga by a very thin margin and shortly emos over it. Also has absolutely superhuman physical endurance, speed, power, stamina, etc., can cast Ki Magic, has godlike summoning powers, etc.
There's also that plot point of that bracelet that keeps popping up, sucking out his power, and vanishing again. And in recent chapters he's been depowered since apparently using all that power overstressed his body or something.
True, but that would be if you left Id to his own devices. He's gotten some crazy powerups from the world he was dropped in, too.
Allow me to throw my own idea, it's a bit of parody and subversion of the god sue, ID was not exactly God mod Sue when it all started, he had reasonable difficulties against experienced people, his "sueness" showed up with Greydone heart and it was promptly subverted since it is a dangerous powerup, he loses himself in power, his heart takes a good toll, aside that he was always on normal mode, then he gets thrown in the past where he is forced to go toe to toe with a God, which means ID had to come up with something, Lamia IS a God made sword, think the equivalent of lance of longuinus but more potent (instead of jesus blood think his father and all of the celestial court blood) so fusing with Lamia was YMMV either an asspull or a desespearte move, which gets subverted again, the powerup is dangerous and it can kill ID, he is learning to controll it and there are people who can still go toe, toe, ID is a natural born genius trained by the elite of the Murim (from what i get Murim=the top masters of martial arts, think if you ever read keiji or played fate/extra an army of Li Shu Wens, or if fan of kenichi, an army of the Grandpa of Miu) so he is restricted, he could bareley go toe to toe with Procas and much less Ceprico, this gets shown too against perser later on and even against Canta, his powerups arent not sufficient to handle all of the Fragments of Chaos, it's a parody since it's obvious any character can get there with effort, just look at grey and "pimple" he pretty much took down a dragon, solo, the dwarf and the mage were sitting ducks all the time.
Ho Yay - Id with pretty much any guy that thinks he's an attractive female. And then there's his relationship with Grey, who constantly tries to spend the night together, alone with him, and "teach him things." But honestly, nothing says it better than this page.
Hilariously, Id also provides a strange Les Yay with women who know he's a man. In one instance Ilrina got all flustered and shy when she saw Id who was accidentally dressed in a pretty dress(he was deep in thought while the dressing was done).