Battle-hardened Bal and The Goddess sound like pre-teens

But when it comes to entertainment, what authors do is emotionally manipulate you. What makes a good story is how well they manipulate readers into conclusions of their own accord. This, however, is not a good story. It's written by someone who's clearly always taking the easy road.

Even in V3C4 Part 3, it is literally the main character's aunt who's narrating everything but when it breaks my suspension of disbelief, I gotta start asking shit. If Aira's (also named Aira bc s*upid tradition made up by author to ''world-build'') and Maria's mother had such a good relationship with her husband that she BLAMED both kids for his death, why didn't she INTRODUCE OR IMPRINT HER PET MONSTER ONTO HIM EVER. It's so dumb bc his death is so contrived and the author didn't think about it and hopes you didn't either. It really doesn't help when everything is revealed through 3rd person narration instead of character dialogue to show how Maria feels about it decades later.

emotionally manipulate you

The MC gets "s**ked in" to another dimension at the age of 15 (Earth age). At this point MC would have already learned about geography, basic biology and chemistry. I remember already learning about the periodic table and participating in simple lab experiments such as burning magnesium strips etc. So the MC definitely has a substantial amount of knowledge leverage over the people living in this medieval magical world and yet he does nothing to make use of it. Hence my conclusion of the author simplifying the novel.

But ok no big deal, I'm not the target audience. Turn off brain and just read, no worries.

My biggest gripe however as always with these kind of novels is that MC transmigrates at age 15 and becomes a baby. Towards the end of the first volume he is age 14 in the other world.

15 + 14 = 29

You'd think his mental age is that but it isn't... It still feels as if he is 15 which doesn't make sense and hence became boring to read. Because there's no complex thinking or plots available when you have an MC built this way. It is for certain at this point till the eventual end of the novel that the story will have a fixed setting and a flawed MC. A very shounen novel for young kids to read.

MC - trained by experienced assassin. He defeats powerful thief/assassin first day after coming to the city. Then fights with guild master on relatively even ground.

Outcome: he is given lowest adventurer rank because he doesn't have much experience fighting humans... Guess what is the first and the only available task for F rank adventurer- killing goblins.

MC is reborn in another world as the son of a king, and is given a "job" (in status screen) - support magic. The king is furious: it's a useless job! He banishes the mother and son to live in an isolated house in some remote forest, accessible only by air transport. A whole staff of servants awaits the two of them in the house.

A dozen chapters later, it turns out that useless job has storage among its skills! Yes, yes, that same imbalanced skill of any isekai protagonist - a skill that creates a pocket of space and stops time in it, and is capable of storing hundreds, thousands of kilograms of all sorts of things and products! This skill alone can become the basis for a novel, like "In another world, only I have an inventory!" But who cares about it, right?

Oh, and here's another thing: a maid lived with the boy and his mother for ten years. In fact, she is an assassin who works for the king. Her mission is to kill the boy if the king can conceive a new son. Why the assassin should pretend to be a maid and spend time with the boy and teach him all sorts of things, like martial arts, is beyond me.

v3c2 when you have monster controller adventurer told to kidnap civilian, seemingly forgetting that an adventurer hurting civilian risk getting their credentials revoked. It would be fine if there's at least a mention the controller adventurer dude thinking twice because of such risk, but it's written like there was no such rule in the first place (it's a rule only a few chapter previously mentioned).

There's an elf as*hole who's antagonistic towards the MC but MC beats his ass and captures him the second time. They even discuss with the other elves that they found a good place to imprison him. However, the second time just simply forgotten and in the next chapter they say that "his whereabouts are unknown".

Also later there's another 2-bit meathead tr*sh who's obsessed with fighting the MC. There's a tournament-like thingy and the guy says that he wants to be his next opponent. But then he's told that the next match is already decided and MC will be fighting a swordmaster (meathead tr*sh even knows who that is). They agree that meathead tr*sh can fight MC in the match after that. Then, MC proceeds to fight with a random giant, and after that a random samurai chick, not the swordmaster and the meathead tr*sh.

There's also the thing that they sometimes completely forget about crucial information. They are supposed to fight an undead dragon that cannot fight in the sunlight. However, they expected rain and cloudy weather for the time of the attack, so they decided that it would be bad to fight it openly and they should defend the city instead. Next chapter, they proceed to leave anyway, and when they 'realize' that the clouds are coming, they hurry back to the city as if the conversations about it never even happened.